If the AutoScroll of RadSplitContainer is true and I scroll the container a little, don’t work the resizes of the panels. sample code: public Form1() { InitializeComponent(); RadSplitContainer radSplitContainer1 = new RadSplitContainer() { Dock = DockStyle.Fill, AutoScroll = true }; this.Controls.Add(radSplitContainer1); for (int i = 0; i < 10; i++) { var panel = new SplitPanel(); panel.SizeInfo.SizeMode = SplitPanelSizeMode.Absolute; panel.SizeInfo.AbsoluteSize = new Size(100, 0); radSplitContainer1.SplitPanels.Add(panel); } }