<Columns> <asp:TemplateField> <ItemTemplate> <asp:HiddenField runat="server" ID="txtHidden" Value='< %# Bind("NameOfFieldOrProperty") %>' /> </ItemTemplate> </asp:TemplateField>The only real "trick" to getting the value is to use FindControl on the row of the grid to get a reference to the hidden control:
HiddenField hidden = gdrow.FindControl("txtHidden") as HiddenField; if (hidden != null) { // Access hidden.Text to retrieve value from control }