Things You'll Need
Instructions
Fire Red/Leaf Green Method
Go to the Safari Zone and pay 500 P.
Go to either the Safari Zone Entrance, or to the second zone.
Walk around until Chansey appears. There is about a 1% chance it will appear. This could take anywhere from five minutes to five hours.
Diamond/Pearl Method 1
Go to Route 209.
Find a patch of grass.
Walk around in the grass. There is 5% chance of finding a wild Chansey.
Diamond/Pearl Method 2
Catch a Happiny in the Trophy Garden or hatch one. A Happiny Egg can be gotten at the Hearthome City Gate.
Find a Oval Stone in the Lost tower.
Equip the Lost stone between 4:00 am and 7:59 pm.
Level up Happiny once and it will evolve into Chansey.