diff --git a/doc/changelog.d/6678.fixed.md b/doc/changelog.d/6678.fixed.md
new file mode 100644
index 00000000000..6d749e5a72e
--- /dev/null
+++ b/doc/changelog.d/6678.fixed.md
@@ -0,0 +1 @@
+Added property file unit to import_3d model
diff --git a/src/ansys/aedt/core/application/analysis_3d.py b/src/ansys/aedt/core/application/analysis_3d.py
index 7519db69e7d..ab55af2cd05 100644
--- a/src/ansys/aedt/core/application/analysis_3d.py
+++ b/src/ansys/aedt/core/application/analysis_3d.py
@@ -533,6 +533,7 @@ def import_3d_cad(
         reduce_percentage=0,
         reduce_error=0,
         merge_planar_faces=True,
+        input_file_unit="Auto",
     ):
         """Import a CAD model.
 
@@ -570,6 +571,8 @@ def import_3d_cad(
             Error percentage during STL reduction operation. The default is ``0``.
         merge_planar_faces : bool, optional
             Whether to merge planar faces during import. The default is ``True``.
+        input_file_unit: str, optional
+            Uinit for the stl file.
 
         Returns
         -------
@@ -595,6 +598,7 @@ def import_3d_cad(
             reduce_percentage=reduce_percentage,
             reduce_error=reduce_error,
             merge_planar_faces=merge_planar_faces,
+            input_file_unit=input_file_unit,
         )
 
     @pyaedt_function_handler(
diff --git a/src/ansys/aedt/core/modeler/cad/primitives.py b/src/ansys/aedt/core/modeler/cad/primitives.py
index 1cb434a23c0..aa665db430d 100644
--- a/src/ansys/aedt/core/modeler/cad/primitives.py
+++ b/src/ansys/aedt/core/modeler/cad/primitives.py
@@ -4911,6 +4911,7 @@ def import_3d_cad(
         reduce_error=0,
         merge_planar_faces=True,
         merge_angle=0.02,
+        input_file_unit="Auto",
     ):
         """Import a CAD model.
 
@@ -4949,6 +4950,8 @@ def import_3d_cad(
             Stl automatic planar face merge during import. Default is ``True``.
         merge_angle : float, optional
             Stl import angle in radians for which faces will be considered planar. Default is ``2e-2``.
+        input_file_unit: str, optional
+            Uinit for the stl file.
 
         Returns
         -------
@@ -4973,7 +4976,6 @@ def import_3d_cad(
         vArg1.append("ImportFreeSurfaces:="), vArg1.append(import_free_surfaces)
         vArg1.append("GroupByAssembly:="), vArg1.append(group_by_assembly)
         vArg1.append("CreateGroup:="), vArg1.append(create_group)
-        vArg1.append("STLFileUnit:="), vArg1.append("Auto")
         (
             vArg1.append("MergeFacesAngle:="),
             vArg1.append(merge_angle if input_file.endswith(".stl") and merge_planar_faces else -1),
@@ -4988,6 +4990,7 @@ def import_3d_cad(
         vArg1.append("ImportMaterialNames:="), vArg1.append(import_materials)
         vArg1.append("SeparateDisjointLumps:="), vArg1.append(separate_disjoints_lumped_object)
         vArg1.append("SourceFile:="), vArg1.append(input_file)
+        vArg1.append("STLFileUnit:="), vArg1.append(input_file_unit)
         self.oeditor.Import(vArg1)
         if refresh_all_ids:
             self.refresh_all_ids()