diff --git a/packages/block-library/src/media-text/edit.js b/packages/block-library/src/media-text/edit.js
index c4749df01ee8a..5cf7928563d61 100644
--- a/packages/block-library/src/media-text/edit.js
+++ b/packages/block-library/src/media-text/edit.js
@@ -318,11 +318,11 @@ function MediaTextEdit( {
 						onDrag={ imperativeFocalPointPreview }
 					/>
 				) }
-			{ mediaType === 'image' && ( mediaUrl || featuredImageURL ) && (
+			{ mediaType === 'image' && mediaUrl && ! useFeaturedImage && (
 				<TextareaControl
 					__nextHasNoMarginBottom
 					label={ __( 'Alternative text' ) }
-					value={ mediaAlt || featuredImageAlt }
+					value={ mediaAlt }
 					onChange={ onMediaAltChange }
 					help={
 						<>
diff --git a/packages/block-library/src/media-text/index.php b/packages/block-library/src/media-text/index.php
index eff4bb1ddaeab..f828aed645fb1 100644
--- a/packages/block-library/src/media-text/index.php
+++ b/packages/block-library/src/media-text/index.php
@@ -48,6 +48,7 @@ function render_block_core_media_text( $attributes, $content ) {
 	}
 	$processor->set_attribute( 'src', esc_url( $current_featured_image ) );
 	$processor->set_attribute( 'class', 'wp-image-' . get_post_thumbnail_id() . ' size-' . $media_size_slug );
+	$processor->set_attribute( 'alt', trim( strip_tags( get_post_meta( get_post_thumbnail_id(), '_wp_attachment_image_alt', true ) ) ) );
 
 	$content = $processor->get_updated_html();