If I accidentally deleted pictures on my digital camera, is there a way to get them back? I have a Nikon 4600?

There is a possibility. Provided it has an internal memory. You will need to call Nikon and ask for assistance. If it was on a memory card/stick, you're out of luck, more than likely. Most internal memories however have 'tracks' that can possibly be reteived. If it is something you REALLY want, I wouldn't do anything else with the camera and call Nikon right away.
Good Luck!

No it is erased from the memory, it is gone.

I have a photo recovery program that allows me to do this (not that I rely on it!) Stop using that memory card and perhaps you can recover them, too, but you won't be able to if you "write" new pictures over it. I don't have the name of the program in front of me, but I could dig it out of storage, if you wanted to email tenweekjtf@yahoo.com

operative word here is "deleted"

for some cases, there is a possibility.