diff --git a/io_scene_psk_psa/helpers.py b/io_scene_psk_psa/helpers.py
index 8c5c69c..937ea05 100644
--- a/io_scene_psk_psa/helpers.py
+++ b/io_scene_psk_psa/helpers.py
@@ -1,8 +1,9 @@
 import datetime
 from collections import Counter
-from typing import List
+from typing import List, Iterable
 
-from bpy.types import NlaStrip
+from bpy.types import NlaStrip, Object
+from .types import BoneGroupListItem
 
 
 class Timer:
@@ -56,7 +57,26 @@ def get_nla_strips_in_timeframe(object, frame_min, frame_max) -> List[NlaStrip]:
     return strips
 
 
-def populate_bone_group_list(armature_object, bone_group_list):
+def populate_bone_group_list(armature_object: Object, bone_group_list: Iterable[BoneGroupListItem]) -> None:
+    """
+    Updates the bone group collection.
+
+    Bone group selections are preserved between updates unless none of the groups were previously selected;
+    otherwise, all groups are selected by default.
+    """
+    has_selected_groups = any([g.is_selected for g in bone_group_list])
+    unassigned_group_is_selected, selected_assigned_group_names = True, []
+
+    if has_selected_groups:
+        # Preserve group selections before clearing the list.
+        # We handle selections for the unassigned group separately to cover the edge case
+        # where there might be an actual group with 'Unassigned' as its name.
+        unassigned_group_idx, unassigned_group_is_selected = next(iter([
+            (i, g.is_selected) for i, g in enumerate(bone_group_list) if g.index == -1]), (-1, False))
+
+        selected_assigned_group_names = [
+            g.name for i, g in enumerate(bone_group_list) if i != unassigned_group_idx and g.is_selected]
+
     bone_group_list.clear()
 
     if armature_object and armature_object.pose:
@@ -66,14 +86,14 @@ def populate_bone_group_list(armature_object, bone_group_list):
         item.name = 'Unassigned'
         item.index = -1
         item.count = 0 if None not in bone_group_counts else bone_group_counts[None]
-        item.is_selected = True
+        item.is_selected = unassigned_group_is_selected
 
         for bone_group_index, bone_group in enumerate(armature_object.pose.bone_groups):
             item = bone_group_list.add()
             item.name = bone_group.name
             item.index = bone_group_index
             item.count = 0 if bone_group not in bone_group_counts else bone_group_counts[bone_group]
-            item.is_selected = True
+            item.is_selected = bone_group.name in selected_assigned_group_names if has_selected_groups else True
 
 
 def get_psa_sequence_name(action, should_use_original_sequence_name):