where can i get a lucario on Pokemon diamond?

Answer 1

you must get an egg ...from iron island...from there ...just atc the egg and get the lucario baby pokmn......then make that pokmn like u ...then when its tamenes is at max...and then it lvls up...it will evolve to lucario.......(awesome pokmnn)

Answer 2

When You go to IRon island, you will tag team with someone who will give you an egg after you finish battling with her thorugh the cave. The egg contains a riolu which evolves into lucario. The riolu evolves through happiness which can be uped through the massage person in one of the cities(i forget). If you have any other ?'s, serebii.net has alot of good info for pokemon.