diff --git a/nion/swift/ExportDialog.py b/nion/swift/ExportDialog.py
index 3c55584b..e4a3ebfc 100644
--- a/nion/swift/ExportDialog.py
+++ b/nion/swift/ExportDialog.py
@@ -261,15 +261,18 @@ class UnitType(enum.Enum):
 
 
 class ExportSizeModel(Observable.Observable):
-    def __init__(self, display_item: DisplayItem.DisplayItem) -> None:
+    def __init__(self, display_item: DisplayItem.DisplayItem, units_persistent_model: UserInterface.StringPersistentModel) -> None:
         super().__init__()
+        self.__units_persistent_model = units_persistent_model
         display_size = self.__calculate_display_size_in_pixels(display_item)
         self.__width = display_size.width
         self.__height = display_size.height
         self.__aspect_ratio = self.__width / self.__height
-        self.__units = UnitType.PIXELS
         self.__float_to_string_converter = Converter.FloatToStringConverter()
-        self.__primary_field = 'width'  # Primary field to determine which text is calculated
+        self.__primary_field = 'width'  # Primary field to determine which text is calculater
+        # Load the persisted units value, default to PIXELS if not found
+        persisted_units = self.__units_persistent_model.value
+        self.__units = UnitType[str(persisted_units)]
 
     def __calculate_display_size_in_pixels(self, display_item: DisplayItem.DisplayItem) -> Geometry.IntSize:
         if display_item.display_data_shape and len(display_item.display_data_shape) == 2:
@@ -327,6 +330,7 @@ def units(self, new_units: int) -> None:
         new_enum = UnitType(new_units)
         if self.__units != new_enum:
             self.__units = new_enum
+            self.__units_persistent_model.value = self.__units.name
             self.notify_property_changed("width")
             self.notify_property_changed("height")
             self.notify_property_changed("width_text")
@@ -391,7 +395,12 @@ def __init__(self, document_controller: DocumentController.DocumentController,
         super().__init__()
         self.__document_controller = document_controller
         self.__display_item = display_item
-        self.__model = ExportSizeModel(display_item)
+        self.__units_persistent_model = UserInterface.StringPersistentModel(
+            ui=document_controller.ui,
+            storage_key="export_units",
+            value=UnitType.PIXELS.name  # Default value if not found
+        )
+        self.__model = ExportSizeModel(display_item, self.__units_persistent_model)
         self.__handler = ExportSVGHandler(self.__model)
         self.__init_ui()