The easiest way to catch Mew in Pokemon Red/Blue/Yellow
Ever wanted to fill that 151st spot of the Pokédex in you Pokémon Red, Blue, or Yellow version? Here is how to do it while keeping your game file safe.
Note: I have captured Mew with this process many, many times and it has not corrupted or broken any of my games.
What you will need:
1. An Abra that knows teleport, this will be a little tough as Abra is rare and will use Teleport as soon as you encounter it. Either immediately throw a ball at it or try to put it to sleep. You can find an Abra on Route 24/25
2. You see trainer number 4 in the image above? Make sure you have not fought him yet. If you have, this specific method will not work.
3. You see trainer number 7 in the image below hiding in the grass on the left? Make sure you haven't fought him either.
4. Have lots of Pokéballs and be ready to capture Mew. It will be level 7 every time, so make sure you are stocked up on whatever you need. Ideally you will want a Pokémon who can paralyze Mew or put it to sleep.
The Capture Method
Now, the first step to catching Mew is to walk in front of trainer number 7 and pressing start at the exact same time that you walk in front of him. If you get it right, it should look something like this. Be sure to go straight down at him, do not go from the side.
Save near the trainer before attempting this first step, just in case you need to try a few times. But once you get the same screen as above, go into your Pokémon and have Abra teleport to the Cerulean Pokémon Center.
Okay, you have completed the first step, and now that you are at the Pokémon Center walk up the Nugget Bridge and fight the trainer seen in the image below. Be sure to walk against the wall just like the image shows. If you walk up close to him in order to initiate the fight, your game will freeze.
Defeat the Youngster Trainer, and then teleport once again back to the Cerulean Pokemon Center. Now, just walk up the Nugget Bridge once again. Your start screen will randomly pop up, so just exit out and keep walking.
Now Mew will appear. Congrats! Now you just need to catch it.
Once again, if you would like to see it all done in video form I recorded a video just for you so click here!