It depends on the video cards specs and what it can handle.
I know I added a spare processor fan to the heat sink of my Nvidia 6200 AGP card and it worked tremendously in dropping the chip temp 10 degrees. Of course I had to alter the fins a bit to accommodate the fans mounting screws.
If you have an open slot next to the video card, this device should do the trick.
You didn't offer much info on the video card or what type of desktop case you have, but any increase in air-flow inside the case will help.
Edited by MrBruce1959, 06 April 2010 - 09:59 AM.