You do not need to find all of the Pokemon. Depending on the game, you'll either get it by following the storyline at some point, or need to find a specific number of Pokemon.
well you need to have all your Pokemon in your pokedex and when you get your national pokedex you will get breed
You do need the national pokedex for the Pokemon modifier. the Pokemon modifier uses the national pokedex numbes. you can not use the sinno pokedex.
if you meen the national dex then you need to find every Pokemon in the sinnoh pokedex
In Pokemon Diamond and Pearl you need the National Pokedex to get Magnemite. In Pokemon Platinum you don't need the National Pokedex to get Magnemite.
you need 150 Pokemon to get the national pokedex
Alright actually you can get Cranidos in pearl. All you need is the national pokedex. Go back to the underground until you find the fossil but you do need the national pokedex to find it.
You need to get the national pokedex to get national pokedex you need to get all the Pokemon and you need to talk to daun's sister
you need to find 210 Pokemon to complete the pokedex
this happened to me. to get the national pokedex in pearl you need to find 150 Pokemon for the sinnoh. then go to sandgem town than in to professors lab and talk to him and oak than he will give the national pokedex then you need to go to the survival area i think. hope it helped :D
The national pokedex.
you need the national pokedex
You need to collect every Pokemon in the National Pokedex - in other words, complete the Pokedex.