From MSDN: "Unlike the ComboBox control, the DataGridViewComboBoxCell does not have SelectedIndex and SelectedValue properties. Instead, selecting a value from a drop-down list sets the cell Value property." I am not sure what will happen when you set the value, although I will assume that it will change the selection. You can then read the Value property to get the value back. There is a way you can make your own selected index property by comparing each item to the Value property and returning the index when the objects match. Hope this helps.