diff --git a/res/css/_components.scss b/res/css/_components.scss
index a6e1f81583..3fc7468539 100644
--- a/res/css/_components.scss
+++ b/res/css/_components.scss
@@ -106,6 +106,7 @@
 @import "./views/elements/_AddressTile.scss";
 @import "./views/elements/_DesktopBuildsNotice.scss";
 @import "./views/elements/_DirectorySearchBox.scss";
+@import "./views/elements/_DesktopCapturerSourcePicker.scss";
 @import "./views/elements/_Dropdown.scss";
 @import "./views/elements/_EditableItemList.scss";
 @import "./views/elements/_ErrorBoundary.scss";
diff --git a/res/css/views/elements/_DesktopCapturerSourcePicker.scss b/res/css/views/elements/_DesktopCapturerSourcePicker.scss
new file mode 100644
index 0000000000..69dde5925e
--- /dev/null
+++ b/res/css/views/elements/_DesktopCapturerSourcePicker.scss
@@ -0,0 +1,72 @@
+/*
+Copyright 2021 Šimon Brandner <simon.bra.ag@gmail.com>
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+.mx_desktopCapturerSourcePicker {
+    overflow: hidden;
+}
+
+.mx_desktopCapturerSourcePicker_tabLabels {
+    display: flex;
+    padding: 0 0 8px 0;
+}
+
+.mx_desktopCapturerSourcePicker_tabLabel,
+.mx_desktopCapturerSourcePicker_tabLabel_selected {
+    width: 100%;
+    text-align: center;
+    border-radius: 8px;
+    padding: 8px 0;
+    font-size: $font-13px;
+}
+
+.mx_desktopCapturerSourcePicker_tabLabel_selected {
+    background-color: $tab-label-active-bg-color;
+    color: $tab-label-active-fg-color;
+}
+
+.mx_desktopCapturerSourcePicker_panel {
+    display: flex;
+    flex-wrap: wrap;
+    justify-content: center;
+    align-items: flex-start;
+    height: 500px;
+    overflow: overlay;
+}
+
+.mx_desktopCapturerSourcePicker_stream_button {
+    display: flex;
+    flex-direction: column;
+    margin: 8px;
+    border-radius: 4px;
+}
+
+.mx_desktopCapturerSourcePicker_stream_button:hover,
+.mx_desktopCapturerSourcePicker_stream_button:focus {
+    background: $roomtile-selected-bg-color;
+}
+
+.mx_desktopCapturerSourcePicker_stream_thumbnail {
+    margin: 4px;
+    width: 312px;
+}
+
+.mx_desktopCapturerSourcePicker_stream_name {
+    margin: 0 4px;
+    white-space: nowrap;
+    text-overflow: ellipsis;
+    overflow: hidden;
+    width: 312px;
+}
diff --git a/src/CallHandler.tsx b/src/CallHandler.tsx
index 9dee7594ea..b5d4ed155f 100644
--- a/src/CallHandler.tsx
+++ b/src/CallHandler.tsx
@@ -82,6 +82,7 @@ import CountlyAnalytics from "./CountlyAnalytics";
 import {UIFeature} from "./settings/UIFeature";
 import { CallError } from "matrix-js-sdk/src/webrtc/call";
 import { logger } from 'matrix-js-sdk/src/logger';
+import DesktopCapturerSourcePicker from "./components/views/elements/DesktopCapturerSourcePicker"
 import { Action } from './dispatcher/actions';
 import { roomForVirtualRoom, getOrCreateVirtualRoomForRoom } from './VoipUserMapper';
 import { addManagedHybridWidget, isManagedHybridWidgetEnabled } from './widgets/ManagedHybrid';
@@ -572,7 +573,15 @@ export default class CallHandler {
                 });
                 return;
             }
-            call.placeScreenSharingCall(remoteElement, localElement);
+
+            call.placeScreenSharingCall(
+                remoteElement,
+                localElement,
+                async () : Promise<DesktopCapturerSource> => {
+                    const {finished} = Modal.createDialog(DesktopCapturerSourcePicker);
+                    const [source] = await finished;
+                    return source;
+                });
         } else {
             console.error("Unknown conf call type: %s", type);
         }
diff --git a/src/components/views/elements/DesktopCapturerSourcePicker.tsx b/src/components/views/elements/DesktopCapturerSourcePicker.tsx
new file mode 100644
index 0000000000..e53683b0ef
--- /dev/null
+++ b/src/components/views/elements/DesktopCapturerSourcePicker.tsx
@@ -0,0 +1,166 @@
+/*
+Copyright 2021 Šimon Brandner <simon.bra.ag@gmail.com>
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import React from 'react';
+import { _t } from '../../../languageHandler';
+import BaseDialog from "..//dialogs/BaseDialog"
+import AccessibleButton from './AccessibleButton';
+import {getDesktopCapturerSources} from "matrix-js-sdk/src/webrtc/call";
+
+export interface DesktopCapturerSource {
+    id: string;
+    name: string;
+    thumbnailURL;
+}
+
+export enum Tabs {
+    Screens = "screens",
+    Windows = "windows",
+}
+
+export interface DesktopCapturerSourceIProps {
+    source: DesktopCapturerSource;
+    onSelect(source: DesktopCapturerSource): void;
+}
+
+export class ExistingSource extends React.Component<DesktopCapturerSourceIProps> {
+    constructor(props) {
+        super(props);
+    }
+
+    onClick = (ev) => {
+        this.props.onSelect(this.props.source);
+    }
+
+    render() {
+        return (
+            <AccessibleButton
+                className="mx_desktopCapturerSourcePicker_stream_button"
+                title={this.props.source.name}
+                onClick={this.onClick} >
+                <img
+                    className="mx_desktopCapturerSourcePicker_stream_thumbnail"
+                    src={this.props.source.thumbnailURL}
+                />
+                <span className="mx_desktopCapturerSourcePicker_stream_name">{this.props.source.name}</span>
+            </AccessibleButton>
+        );
+    }
+}
+
+export interface DesktopCapturerSourcePickerIState {
+    selectedTab: Tabs;
+    sources: Array<DesktopCapturerSource>;
+}
+export interface DesktopCapturerSourcePickerIProps {
+    onFinished(source: DesktopCapturerSource): void;
+}
+
+export default class DesktopCapturerSourcePicker extends React.Component<
+    DesktopCapturerSourcePickerIProps,
+    DesktopCapturerSourcePickerIState
+    > {
+    interval;
+
+    constructor(props) {
+        super(props);
+
+        this.state = {
+            selectedTab: Tabs.Screens,
+            sources: [],
+        };
+    }
+
+    componentDidMount() {
+        // We update the sources every 500ms to get newer thumbnails
+        this.interval = setInterval(async () => {
+            this.setState({
+                sources: await getDesktopCapturerSources(),
+            });
+        }, 500);
+    }
+
+    componentWillUnmount() {
+        clearInterval(this.interval);
+    }
+
+    onSelect = (source) => {
+        this.props.onFinished(source);
+    }
+
+    onScreensClick = (ev) => {
+        this.setState({selectedTab: Tabs.Screens});
+    }
+
+    onWindowsClick = (ev) => {
+        this.setState({selectedTab: Tabs.Windows});
+    }
+
+    onCloseClick = (ev) => {
+        this.props.onFinished(null);
+    }
+
+    render() {
+        let sources;
+        if (this.state.selectedTab === Tabs.Screens) {
+            sources = this.state.sources
+                .filter((source) => {
+                    return source.id.startsWith("screen");
+                })
+                .map((source) => {
+                    return <ExistingSource source={source} onSelect={this.onSelect} key={source.id} />;
+                });
+        } else {
+            sources = this.state.sources
+                .filter((source) => {
+                    return source.id.startsWith("window");
+                })
+                .map((source) => {
+                    return <ExistingSource source={source} onSelect={this.onSelect} key={source.id} />;
+                });
+        }
+
+        const buttonStyle = "mx_desktopCapturerSourcePicker_tabLabel";
+        const screensButtonStyle = buttonStyle + ((this.state.selectedTab === Tabs.Screens) ? "_selected" : "");
+        const windowsButtonStyle = buttonStyle + ((this.state.selectedTab === Tabs.Windows) ? "_selected" : "");
+
+        return (
+            <BaseDialog
+                className="mx_desktopCapturerSourcePicker"
+                onFinished={this.onCloseClick}
+                title={_t("Share your screen")}
+            >
+                <div className="mx_desktopCapturerSourcePicker_tabLabels">
+                    <AccessibleButton
+                        className={screensButtonStyle}
+                        onClick={this.onScreensClick}
+                    >
+                        {_t("Screens")}
+                    </AccessibleButton>
+                    <AccessibleButton
+                        className={windowsButtonStyle}
+                        onClick={this.onWindowsClick}
+                    >
+                        {_t("Windows")}
+                    </AccessibleButton>
+                </div>
+                <div className="mx_desktopCapturerSourcePicker_panel">
+                    { sources }
+                </div>
+            </BaseDialog>
+        );
+    }
+}
diff --git a/src/i18n/strings/en_EN.json b/src/i18n/strings/en_EN.json
index fcd8202db1..06aeec75fd 100644
--- a/src/i18n/strings/en_EN.json
+++ b/src/i18n/strings/en_EN.json
@@ -1852,6 +1852,9 @@
     "Use the <a>Desktop app</a> to search encrypted messages": "Use the <a>Desktop app</a> to search encrypted messages",
     "This version of %(brand)s does not support viewing some encrypted files": "This version of %(brand)s does not support viewing some encrypted files",
     "This version of %(brand)s does not support searching encrypted messages": "This version of %(brand)s does not support searching encrypted messages",
+    "Share your screen": "Share your screen",
+    "Screens": "Screens",
+    "Windows": "Windows",
     "Join": "Join",
     "No results": "No results",
     "Please <newIssueLink>create a new issue</newIssueLink> on GitHub so that we can investigate this bug.": "Please <newIssueLink>create a new issue</newIssueLink> on GitHub so that we can investigate this bug.",