This is not possible without hacking the property grid. Here is a code that can change the label column's width:

public static void SetLabelColumnWidth(PropertyGrid grid, int width)
{
    if (grid == null)
        throw new ArgumentNullException("grid");

    // get the grid view
    Control view = (Control)grid.GetType().GetField("gridView", BindingFlags.Instance | BindingFlags.NonPublic).GetValue(grid);

    // set label width
    FieldInfo fi = view.GetType().GetField("labelWidth", BindingFlags.Instance | BindingFlags.NonPublic);
    fi.SetValue(view, width);

    // refresh
    view.Invalidate();
}

public static void ResetLabelColumnWidth(PropertyGrid grid)
{
    SetLabelColumnWidth(grid, -1);
}

Use it just like this to remove the label column:

    SetLabelColumnWidth(propertyGrid1, 0);

The reset function restores the label column.

Of course, it's a hack so it may not work in the future. There are also issues:

• The v-splitter cursor is shown when the mouse moves to the grid's left side, and the user can select it and reset the label column if he clicks.
• Some grid actions may also restore the label column (like using the property grid toolbar).

Hope this helps!