it's possible but unnessicarily complicated as you may be running into permission problems.
the simplest way, assuming all your media files are in the default location, would be to connect the two Macs with a firewire cable, boot the source Mac in Target Disk Mode, and copy the entire iTunes folder (not just the iTunes music folder) from <MacintoshHD>/users/yourname/music on the source to <MacintoshHD>/users/yourname/music on the target (overwriting the iTunes folder in place there).
you can also use an external HD. copy the iTunes folder from the old Mac to it, then copy the iTunes folder from the external to the new machine.
however, if you have no other choice, have a look at #15 thru #17 in this user tip.