There is no real transparency in Windows Forms. When you make a control transparent, what actually happens is that the control copies the area of its parent that it is covering and paints that in its background. Because your form is the parent of the PictureBox, what you're seeing is the form painted in its background. You may have to use GDI+ to draw the image over the DataGridView instead, although that may be complex because you may have to draw in each cell individually. I'm not sure that you can just draw over the top of the grid as a whole.