diff --git a/docs/release_notes/next/fix-2490-live-viewer-modified-intensity b/docs/release_notes/next/fix-2490-live-viewer-modified-intensity
new file mode 100644
index 00000000000..a1146f6a3a9
--- /dev/null
+++ b/docs/release_notes/next/fix-2490-live-viewer-modified-intensity
@@ -0,0 +1 @@
+#2490: The Live Viewer Intensity plot now updates correctly when images are modified, i.e. deleted or multiple added files
\ No newline at end of file
diff --git a/mantidimaging/gui/windows/live_viewer/model.py b/mantidimaging/gui/windows/live_viewer/model.py
index 22c0bc1094b..e9ce4d9b7a0 100644
--- a/mantidimaging/gui/windows/live_viewer/model.py
+++ b/mantidimaging/gui/windows/live_viewer/model.py
@@ -183,7 +183,6 @@ def _handle_image_changed_in_list(self, image_files: list[Image_Data]) -> None:
 
     def handle_image_modified(self, image_path: Path) -> None:
         self.presenter.update_image_modified(image_path)
-        self.presenter.notify_update_image_list()
 
     def close(self) -> None:
         """Close the model."""
@@ -192,7 +191,7 @@ def close(self) -> None:
             self.image_watcher = None
         self.presenter = None  # type: ignore # Model instance to be destroyed -type can be inconsistent
 
-    def add_mean(self, image_data_obj: Image_Data, image_array: np.ndarray | None) -> None:
+    def add_mean(self, image_path: Path, image_array: np.ndarray | None) -> None:
         if image_array is None:
             mean_to_add = np.nan
             mean_readable = 0
@@ -203,9 +202,12 @@ def add_mean(self, image_data_obj: Image_Data, image_array: np.ndarray | None) -
         else:
             mean_to_add = np.mean(image_array)
             mean_readable = 1
-        self.mean_paths[image_data_obj.image_path] = (mean_to_add, mean_readable)
-        self.mean = np.array(list(dict(sorted(self.mean_paths.items())).values()))[:, 0]
-        self.mean_readable = np.array(list(dict(sorted(self.mean_paths.items())).values()))[:, 1]
+        self.update_mean_dict(image_path, mean_to_add, mean_readable)
+
+    def update_mean_dict(self, image_path: Path, mean_to_add: float, mean_readable: int) -> None:
+        self.mean_paths[image_path] = (mean_to_add, mean_readable)
+        self.mean = np.array(list(self.mean_paths.values()))[:, 0]
+        self.mean_readable = np.array(list(self.mean_paths.values()))[:, 1]
 
     def clear_mean_partial(self) -> None:
         self.mean_paths = dict.fromkeys(self.mean_paths, (np.nan, 1))
diff --git a/mantidimaging/gui/windows/live_viewer/presenter.py b/mantidimaging/gui/windows/live_viewer/presenter.py
index 49d70d90106..c03867d54b7 100644
--- a/mantidimaging/gui/windows/live_viewer/presenter.py
+++ b/mantidimaging/gui/windows/live_viewer/presenter.py
@@ -110,16 +110,9 @@ def update_image_list(self) -> None:
                 if not self.view.live_viewer.roi_object:
                     self.view.live_viewer.add_roi()
                 self.model.roi = self.view.live_viewer.get_roi()
-                self.model.images = images_list
                 images_list_paths = [image.image_path for image in images_list]
                 if self.old_image_list_paths == images_list_paths[:-1]:
-                    try:
-                        image_data = self.model.image_cache.load_image(images_list[-1])
-                        self.model.add_mean(images_list[-1], image_data)
-                        self.update_intensity_with_mean()
-                    except ImageLoadFailError as error:
-                        logger.error(error.message)
-                        self.model.add_mean(images_list[-1], None)
+                    self.try_add_mean(images_list[-1])
                     self.update_intensity(self.model.mean)
                     self.old_image_list_paths = images_list_paths
                 else:
@@ -132,6 +125,15 @@ def update_image_list(self) -> None:
     def notify_update_image_list(self) -> None:
         self.update_image_list_timer.start(IMAGE_lIST_UPDATE_TIME)
 
+    def try_add_mean(self, image: Image_Data) -> None:
+        try:
+            image_data = self.model.image_cache.load_image(image)
+            self.model.add_mean(image.image_path, image_data)
+            self.update_intensity_with_mean()
+        except ImageLoadFailError as error:
+            logger.error(error.message)
+            self.model.add_mean(image.image_path, None)
+
     def select_image(self, index: int) -> None:
         if not self.model.images:
             return
@@ -196,6 +198,8 @@ def update_image_modified(self, image_path: Path) -> None:
         """
         if self.selected_image and image_path == self.selected_image.image_path:
             self.display_image(self.selected_image)
+            self.try_add_mean(self.selected_image)
+            self.update_intensity_with_mean()
 
     def update_image_operation(self) -> None:
         """