4th Gen how do u get the national dex?

[rishi 20]

same as title how do u get it?

 

[Pkmn Trainer Alex]

After viewing all 150 Sinnoh Region Pokémon, talk to Professor Rowan in Sandgem. I think afterwards, Professor Oak will appear and give you the National Pokédex...don't really remember. Will double-check in a sec.

Edit: K, verified it, that's about right. Just to add, you do not need to beat the Elite 4 first, as long as you can get the necessary Pokédex entries through trading.

 

[-Jirachi-]

That is a great question and will get an ever greater answer.....
You need to have at least seen ALL 150 Shinnoh pokemon then go to the prof and you will view a cut scene involving you, the prof and Oak who will upgrade your normal dex into the national dex trust me im a professional lol :P

 

[diamondpearl876]

When you've seen all of the Pokemon, just talk to Professor Rowan in Sandgem Town. Prof. Oak should come along and give you the National Dex.

 

[Nekonron]

If you need to fill your Pokedex on either Dialga/Palkia (depending on which version you have, chances are you are missing one), you can return to Celestic Town and talk to the old lady (Cynthia's grandmother if I'm not mistaken?) at the big house at the northen side of town. She will show you the picture of the other Legendary to fill your Pokedex.