When you setup a hierarchical RadVirtualGrid and set the UseScrollbarsInHierarchy property to false and use VirtualGridAutoSizeColumnsMode.Fill for the child template, you expect that the column's width is calculated according to the total width of the respective template. Hence, if you shrink or enlarge the grid, the columns will shrink/enlarge respectively. However, if you double click the resize cursor between the column headers you will notice that the best-fit action is performed over the column and its width is adjusted. However, the VirtualGridAutoSizeColumnsMode.Fill setting is not respected and you either can't see all the columns, or you obtain some empty space if the column doesn't need much space.