there are actually 493 Pokemon and you see them all by just playing through the game and searching in all the different routes, also you will need a friend with pearl to see them all, it will take a very long time though
hope that helps
See all 150 Sinnoh Pokemon
you have to get the national dex when you see all 150 Pokemon orif you play platinum you will have to see all 210 Pokemon
there are 150 kinds of Pokemon that you can see and/or obtain. Unless you have friend trade you Pokemon that you can only get in pearl to you, you'll never obtain them all. In Pokemon diamond and pearl all you have to do is see the Pokemon and you get its data unlike the older versions where you have to obtain them.
You can get the National Pokedex in Diamond when you see all 150 Pokemon, but not necessarily capture them.
See all 150 Pokemon in the Sinnoh Dex and talk to Professor Rowan.
You have to see all 150 Pokemon, you don't have to catch them. After that go to Professor Rowan
No all you have to do is SEE the first 150 Pokemon then you shall get the national dex..
for diamond and pearl there are 150 Pokemon u need to see . in plat nium u neeed to see 210 Pokemon.
you have to see all Pokemon in the game (sinoh only) and the go to see rowan the profecer and oak will appear
you have to see 150 Pokemon then talk to professor oak..
The only way you can see all the Pokemon on diamond is by going into the GTS and global trade different Pokemon.
you have to catch all of the pokemon in diamond or SEE all of the pokemon