To reproduce: this.radTreeView1.TriStateMode = true; RadTreeNode sitesNode = radTreeView1.Nodes.Add("Sites", "Sites", ""); sitesNode.Expanded = true; RadTreeNode siteNode = new RadTreeNode("A site"); sitesNode.Nodes.Add(siteNode); RadTreeNode eNode = new RadTreeNode("Event Types"); siteNode.Nodes.Add(eNode); siteNode.Expanded = true; RadTreeNode dummy = new RadTreeNode("dummy"); eNode.Nodes.Add(dummy); dummy.CheckState = ToggleState.On; RadTreeNode dummy2 = new RadTreeNode("dummy2"); eNode.Nodes.Add(dummy2); dummy2.CheckState = ToggleState.Off; Please refer to the attached screenshot. Workaround: change the CheckState property after all nodes are added to RadTreeView. this.radTreeView1.TriStateMode = true; RadTreeNode sitesNode = radTreeView1.Nodes.Add("Sites", "Sites", ""); sitesNode.Expanded = true; RadTreeNode siteNode = new RadTreeNode("A site"); sitesNode.Nodes.Add(siteNode); RadTreeNode eNode = new RadTreeNode("Event Types"); siteNode.Nodes.Add(eNode); siteNode.Expanded = true; RadTreeNode dummy = new RadTreeNode("dummy"); eNode.Nodes.Add(dummy); RadTreeNode dummy2 = new RadTreeNode("dummy2"); eNode.Nodes.Add(dummy2); dummy2.CheckState = ToggleState.Off; dummy.CheckState = ToggleState.On;