Generally no this would be counter productive as you need to rest to grow, and if you have the energy to hit the same bodypart using the same routine then you did'nt put in enough effort in the first workout. However you could split a bodypart like legs or back in that you could train quads in the am and hammies in the pm, or lats ie pullups pulldowns etc in the am, and back ie rows, deads etc in the pm.
I hope this helps....
I've done double day and done it like PS says above. It did work for me for a little time but I was TIRED come evening time and never slept so well. I found my diet had to be spot on to keep up for the double workload.
It does work if you do it right and don't got mental on it.