If you release a Pokemon, can you get it back?

Question

I have been itching to let a Pokemon go, but I don't think I should.

Comments

try it on a patrat lol
Jks besides, my friend hacked a Lugia and a Mewtwo on his Diamond game; he released them, saved, powered off then later, the game said "Mewtwo came back to see you!"--> I guess hacks may come back.

Answer 1

No, if you release a Pokémon you can not get it back. The only way would be to turn off the game without saving.