diff --git a/src/Core/Models/Table/GroupUser.cs b/src/Core/Models/Table/GroupUser.cs
new file mode 100644
index 0000000000..524fedd366
--- /dev/null
+++ b/src/Core/Models/Table/GroupUser.cs
@@ -0,0 +1,11 @@
+using System;
+using Bit.Core.Utilities;
+
+namespace Bit.Core.Models.Table
+{
+    public class GroupUser
+    {
+        public Guid GroupId { get; set; }
+        public Guid OrganizationUserId { get; set; }
+    }
+}
diff --git a/src/Core/Repositories/IGroupRepository.cs b/src/Core/Repositories/IGroupRepository.cs
index 56065b7cf9..837c4522d0 100644
--- a/src/Core/Repositories/IGroupRepository.cs
+++ b/src/Core/Repositories/IGroupRepository.cs
@@ -12,6 +12,7 @@ namespace Bit.Core.Repositories
         Task<ICollection<Group>> GetManyByOrganizationIdAsync(Guid organizationId);
         Task<ICollection<GroupUserDetails>> GetManyUserDetailsByIdAsync(Guid id);
         Task<ICollection<Guid>> GetManyIdsByUserIdAsync(Guid organizationUserId);
+        Task<ICollection<GroupUser>> GetManyGroupUsersByOrganizationIdAsync(Guid organizationId);
         Task CreateAsync(Group obj, IEnumerable<SelectionReadOnly> collections);
         Task ReplaceAsync(Group obj, IEnumerable<SelectionReadOnly> collections);
         Task DeleteUserAsync(Guid groupId, Guid organizationUserId);
diff --git a/src/Core/Repositories/SqlServer/GroupRepository.cs b/src/Core/Repositories/SqlServer/GroupRepository.cs
index 4ef8e87f2f..73e65871db 100644
--- a/src/Core/Repositories/SqlServer/GroupRepository.cs
+++ b/src/Core/Repositories/SqlServer/GroupRepository.cs
@@ -77,6 +77,19 @@ namespace Bit.Core.Repositories.SqlServer
             }
         }
 
+        public async Task<ICollection<GroupUser>> GetManyGroupUsersByOrganizationIdAsync(Guid organizationId)
+        {
+            using(var connection = new SqlConnection(ConnectionString))
+            {
+                var results = await connection.QueryAsync<GroupUser>(
+                    $"[{Schema}].[GroupUser_ReadByOrganizationId]",
+                    new { OrganizationId = organizationId },
+                    commandType: CommandType.StoredProcedure);
+
+                return results.ToList();
+            }
+        }
+
         public async Task CreateAsync(Group obj, IEnumerable<SelectionReadOnly> collections)
         {
             obj.SetNewId();
diff --git a/src/Core/Services/Implementations/OrganizationService.cs b/src/Core/Services/Implementations/OrganizationService.cs
index ac00441964..6425c48c67 100644
--- a/src/Core/Services/Implementations/OrganizationService.cs
+++ b/src/Core/Services/Implementations/OrganizationService.cs
@@ -916,27 +916,35 @@ namespace Bit.Core.Services
             var existingGroups = (await _groupRepository.GetManyByOrganizationIdAsync(organizationId)).ToList();
             var existingGroupsDict = existingGroups.ToDictionary(g => g.ExternalId);
 
-            var newGroups = groups.Where(g => !existingGroupsDict.ContainsKey(g.ExternalId));
-            var updateGroups = existingGroups.Where(eg => groups.Any(g => g.ExternalId == eg.ExternalId && g.Name != eg.Name));
-
-            foreach(var group in newGroups)
+            if(groups?.Any() ?? false)
             {
-                group.CreationDate = group.RevisionDate = DateTime.UtcNow;
-                await _groupRepository.CreateAsync(group);
-            }
+                var newGroups = groups.Where(g => !existingGroupsDict.ContainsKey(g.ExternalId));
+                var updateGroups = existingGroups.Where(eg => groups.Any(g => g.ExternalId == eg.ExternalId && g.Name != eg.Name));
 
-            foreach(var group in updateGroups)
-            {
-                group.RevisionDate = DateTime.UtcNow;
-                group.Name = existingGroupsDict[group.ExternalId].Name;
-                await _groupRepository.ReplaceAsync(group);
-            }
+                foreach(var group in newGroups)
+                {
+                    group.CreationDate = group.RevisionDate = DateTime.UtcNow;
+                    await _groupRepository.CreateAsync(group);
+                }
 
-            // Add the newly created groups to existing groups so that we have a complete list to reference below for users.
-            existingGroups.AddRange(newGroups);
-            existingGroupsDict = existingGroups.ToDictionary(g => g.ExternalId);
+                foreach(var group in updateGroups)
+                {
+                    group.RevisionDate = DateTime.UtcNow;
+                    group.Name = existingGroupsDict[group.ExternalId].Name;
+                    await _groupRepository.ReplaceAsync(group);
+                }
+
+                // Add the newly created groups to existing groups so that we have a complete list to reference below for users.
+                existingGroups.AddRange(newGroups);
+                existingGroupsDict = existingGroups.ToDictionary(g => g.ExternalId);
+            }
 
             // Users
+            if(users?.Any() ?? false)
+            {
+                return;
+            }
+
             var existingUsers = await _organizationUserRepository.GetManyDetailsByOrganizationAsync(organizationId);
             var existingUsersDict = existingUsers.ToDictionary(u => u.Email);
 
@@ -975,6 +983,7 @@ namespace Bit.Core.Services
                 }
             }
 
+            var existingGroupUsers = await _groupRepository.GetManyGroupUsersByOrganizationIdAsync(organizationId);
             foreach(var user in updateUsers)
             {
                 if(!existingUsersDict.ContainsKey(user.Key))
@@ -983,11 +992,16 @@ namespace Bit.Core.Services
                 }
 
                 var existingUser = existingUsersDict[user.Key];
-                var groupsIdsForUser = user.Value.Where(id => existingGroupsDict.ContainsKey(id))
-                        .Select(id => existingGroupsDict[id].Id).ToList();
-                if(groupsIdsForUser.Any())
+                var existingGroupIdsForUser = new HashSet<Guid>(existingGroupUsers
+                    .Where(gu => gu.OrganizationUserId == existingUser.Id)
+                    .Select(gu => gu.GroupId));
+                var newGroupsIdsForUser = new HashSet<Guid>(user.Value
+                    .Where(id => existingGroupsDict.ContainsKey(id))
+                    .Select(id => existingGroupsDict[id].Id));
+
+                if(!existingGroupIdsForUser.SetEquals(newGroupsIdsForUser))
                 {
-                    await _organizationUserRepository.UpdateGroupsAsync(existingUser.Id, groupsIdsForUser);
+                    await _organizationUserRepository.UpdateGroupsAsync(existingUser.Id, newGroupsIdsForUser);
                 }
             }
         }
diff --git a/src/Sql/Sql.sqlproj b/src/Sql/Sql.sqlproj
index 5f33d0eb0d..becbb1c1d5 100644
--- a/src/Sql/Sql.sqlproj
+++ b/src/Sql/Sql.sqlproj
@@ -189,5 +189,6 @@
     <Build Include="dbo\Stored Procedures\OrganizationUser_CreateWithCollections.sql" />
     <Build Include="dbo\Stored Procedures\OrganizationUser_UpdateWithCollections.sql" />
     <Build Include="dbo\Stored Procedures\CollectionUser_Delete.sql" />
+    <Build Include="dbo\Stored Procedures\GroupUser_ReadByOrganizationId.sql" />
   </ItemGroup>
 </Project>
\ No newline at end of file
diff --git a/src/Sql/dbo/Stored Procedures/GroupUser_ReadByOrganizationId.sql b/src/Sql/dbo/Stored Procedures/GroupUser_ReadByOrganizationId.sql
new file mode 100644
index 0000000000..87d2632134
--- /dev/null
+++ b/src/Sql/dbo/Stored Procedures/GroupUser_ReadByOrganizationId.sql	
@@ -0,0 +1,15 @@
+CREATE PROCEDURE [dbo].[GroupUser_ReadByOrganizationId]
+    @OrganizationId UNIQUEIDENTIFIER
+AS
+BEGIN
+    SET NOCOUNT ON
+
+    SELECT
+        GU.*
+    FROM
+        [dbo].[GroupUser] GU
+    INNER JOIN
+        [dbo].[Group] G ON G.[Id] = GU.[GroupId]
+    WHERE
+        G.[OrganizationId] = @OrganizationId
+END
\ No newline at end of file