How to Get Blissey in Diamond

Speak to the shopkeeper behind the counter in the Hearthrome City Poke Mart. Order 20 to 30 Heal Balls from the shopkeeper for 300 PokeDollars each. A Heal Ball is a type of Pokeball you use to catch Pokemon. Once you catch the Pokemon, the Heal Ball will restore its Hitpoints and Power Points.

Use the eastern exit to leave Hearthrome City. You will find yourself on Route 209. Walk up to the nearest patch of long grass. Chansey has a 5 percent chance of appearing in all patches of long grass on Route 209. Look for wild Pokemon in the long grass until you come across a Chansey.

Lower the Chansey's Hitpoints with Fighting-type moves. Don't defeat the Chansey. If you defeat a wild Pokemon, you won't be able to capture it. Once it has less than 30 hitpoints, fling Heal Balls at it. After about a dozen Heal Balls, you will capture the Chansey.

Pick berries from the dirt patches around Sinnoh. Feed them to your Chansey to raise its happiness. Make it consume Pokemon Vitamins, leave it in your party and use it to battle Pokemon. Do these things until the girl in the Pokemon Fan Club of Hearthrome City says, "It looks really happy! It must love you a lot" about your Chansey.

Make your Chansey gain experience by battling Pokemon Trainers, wild Pokemon and Gym Leaders. Once it gains enough experience to advance to the next level, it will evolve into Blissey.