You will encounter Prof.Oak in Prof.Rowan's Lab and you will receive Poke Radar and Prof.Oak will ask you to come to the Pal Park where he will give you a National Pokedex.
get an action replay, get the fill pokedex cheat, then u have full pokedex!
luck You CAN get shiny Pokemon WITHOUT a full Pokedex(I have done it :P)
get an action replay, get Pokemon modifier and full pokedex cheats, then find arceas!
You need to get the official Pokemon full pokedex guide vol 2
after you beat elite4 and champ you have to get full pokedex to go to stark mountain and tons of slugma and macargos
you only have to see every Pokemon that lives in the reigon. To find out where they all are, use this site. http://bulbapedia.bulbagarden.net/wiki/Main_Page
i dont think you can get a code to have all of the pokemon, but a code comes with the AR to have a full pokedex
www.legendarypokemon.net has a full pokedex, and details on how to get each pokemon.
Since there is quite a lot of Pokemon in Pearl, go to pokemon.marriland.com. On the left hand side under Pokemon Pearl/Diamond, click Pokedex and there will be a full list under.
To get a full National Pokedex, You need to use the Action Replay Chip thingy... I did it! It's really ez X-cept for getting the code because some people lie about the numbers on the code... >:(
Catch all Pokemon
You can't. Not without and not with the national dex, ou can't get to other regions at all in Pokemon Diamond and Pearl