Actually if you're just trying to complete your pokedex you don't need to physically see him. Once you beat the Elite 4 (it might actually be before this) you can go talk to the elderly woman in Celestic Town. I went to Sandgem town and talked to my kid friend or whatever and he told me that she needed to talk to me. She shows you a picture of Palkia and tells you that apparently there are 2 legendary pokemon. That seemed to be enough to complete my pokedex.
The only way to see Palkia in Pokémon Diamond is to use WiFi. Otherwise, you can't.
You cannot battle Palkia in Diamond however you can go talk to Cynthia's Grandma in Celestic Town in order to see it.
Palkia is not available in Pokemon Diamond. You'll have to receive one in a trade. To just SEE Palkia (but not catch it), go to Celestic Town after beating Cynthia. An old lady in the top house will show you a book. It has Palkia, and it'll be added to your POkedex.
You cannot catch palkia in pokemon diamond!
You cant get palkia in diamond if you play diamond and you trade you STILL cant get palkia only in pearl you can get palkia
Only by trading from Diamond. In Pokemon Pearl you get Palkia and in Pokemon Diamond you get Dialga.
You cannot catch Palkia in Pokemon Diamond
It would be where you see dialga or palkia in the beginning.
You can't see palkia on Pokemon diamond unless you trade. However, it will be added in the pokedex after you've seen dialga and visited the elder of Celestic toen. She will show you a picture of palkia.
From what I know, no. To see Palkia on Diamond or Pearl, catch or trade. Hope I helped. Sorry.
You can't, just as you can't see dialga in pearl. Get platinum if you want both.