To reproduce: public Form1() { InitializeComponent(); for (int i = 0; i < 15; i++) { RadButton btn = new RadButton(); btn.Text = "Item" + i; btn.Dock = DockStyle.Bottom; this.radCollapsiblePanel1.PanelContainer.Controls.Add(btn); } } Please refer to the attached screenshot.
When controls are docked, the scroll bar will not be shown. To show the scroll bars, assign Location to the controls and when it is outside the control bounds, scrollbars will be shown.