I Used the treat method. Lots and lots of praise and an M&M (or whatever he likes) for a job well done. Also, try a potty party. Tell him the potty fairy is coming with a potty doll and gifts for him. Build this up for a few weeks, telling him she only comes when big boys are ready. Buy lots of small gifts, some being big boy underwear, special wipes for the potty, that kind of thing. Wrap them and surprise him one morning. Then spend the whole day watching potty videos and playing potty games. Get a "PAUL" doll by Corelle as one of the gifts. He is anatomically correct and explain that your son has to help you train Paul to use the potty. (he comes with a potty and underwear and bottle)You spend the first half of the day training Paul. He gets a treat each time he pees or poops (apple juice for pee, sneek in a tootsie roll for poop) Give the treat to your son, explaining that he can have the treat since he did such a good job helping you train Paul. The second half of the day you spend training your son. Lots and lots and lots to drinks. Every time he goes on the potty, make the biggest deal you can. Do a "Potty dance and song" Think of the biggest fool you can make of yourself, then do a little more. The more fun and exciting it is, the more he will want to repeat it. And each time he goes, he gets a treat. I had a tray of small espresso paper cups with different treats. Raisins, fruit loops, M&Ms, Mike and Ikes, etc. Let him pick, but save something big for the poop. Also, tell him if he does a great job and goes on the potty, you will have a potty party. Whether it be at home with special family, his favorite McDonalds or Chucky Cheese, just have a party that night to celebrate his big boy efforts. And dont sweat it. I've never seen a child in kindergarten in diapers, he'll get it. One pit fall, which I just posted about. I am not sure how to get him off the treats now. I'll let you know what advise I get on this. The potty party really works though. Good luck.