How do you catch up to suicune when he is runnig around the whole region..

You must have chosen Charmander. If you have already used your Masterball, then you may want to try using moves like MEAN LOOK or use a Diglett or Dugtrio because they usually have a special power called ARENA TRAP, these moves will stop any thing from running away, don't forget to put Suicune to sleep and lower it down slowly, incase you end up killing it.
Hope you catch him, good luck.

Just keep looking around grass.

P.S. If you Fly or enter a building his location changes

Suicune changes routes everytime you change routes or when you turn it off and on. So you can do this go to a pach of grass and save there. Then turn it off and on and check the Pokedex and see if suicune changed routes. In a while suicune will come to u. Also suicune doesnt heal when you encounter him so you can paralyze him then weaken it then try to catch it.

I believe you must wait. It stops running eventually. ~crystasky98~

What I did was:
1)Fly to viradian city.
2)keep on going in and out of the Pokemon center until he is on Route 22,Route 1 or Route 2.
3)go to the place where ever he is and pokeball go!
If he runs repeat steps 2 to 3.

You just chase him until' you find him. He doesn't run anywhere, he runs away from you, so try forcing him into the place you want him to go. Then use Sweet Scent and there will be a big chance you will find him. When you've found him use Mean Look on him so he can't escape. Suicune can't learn Roar!

You just have to get lucky. Also, you must check EVERY patch of grass because Suicune is in a certain spot on a route. I like to buy Repels and then walk around with a Pokemon at level 40 or lower, then if suicune is in a route, you will know because Repel repels all Pokemon that are at a lower level than you. And a useful tip, Super repels are the best choice because you get more for your money. Just a little tip so you don't waste your money. But you really actually have to get lucky. And don't try to Fly to where suicune is, because that won't work, suicune will just run farther away, and you will have achieved nothing. Good luck.

Well I have only just caught mine about 2 hours ago what you do is observie it's pattern and judge where it will be at the next point it's realy easy to catch also :D

Suicine is much like Latios/Latias of Ruby/Sapphire, you'll see him in random battles in tall grass. Once you meet him once tho if he gets away he should show up in AREA on your Pokedex.

It is completely random when you find him. A good way to find him faster is using a high leveled Pokemon who's level does not surpass 40 with a Max Repel, this will keep all Pokemon who's level is lower then yours away. Also another good way of catching it when it appears is having a Pokemon with the ability trait "Soundproof" This blocks all noise or sound based attacks, you will need it for Suicune's Roar attack. (A good example of something that could have the trait "Soundproof" is Electrode, or Mr. Mime.)

What happens is you have to hunt them down. Once you have seen them then it will appear on you Pokedex. It will go to another place every time you anter another place, building or route. When you are in the same route as one of them then save just in case you kill it you can switch your game off then on again but it wont be in that same place. When you do see one then try to get it to sleep whilst sleeping try to get it's health down. Then you can capture it. If you poison or paralyse one then it wont stick so don't try to paralyse it beacause it's a waist of time. When you se it the next time it will be gone. Hope that helped. Rakz..

It is hard and takes alot of focus and strategy but here is how I do it.

First get to some where that the town can go to a feild without going through any doors. (Like Viridian) Be prepared with a bunch of Ultra Balls, and a Wobuffet (Cerulean Cave), which has an effect that prevents escaping or use of Roar or Whirlwind. If your not that far, get something fast with Mean Look so he can't escape as easy, *he will be able to use Roar. If he succeeds in using Roar, he will dissapear from the game. (I had an Entei pull that on my brother.)

Every time you change to a different area Suicune will also change. Once in a good location, check your Pokedex to see where he is. If he is two away from an area next to you go toward that area. Sometimes he will go toward the town and be in the same area you went to. If the plan fails, Fly, not walk, to the same town you were just at. It will make Suicune move to a new area. Then try again.

The way I do it is by using max repels and going aroud all of the grass. If you try to Fly to the places then Suicune will go away.