My son was potty trained and then backslid twice before it finally stuck the third time. The first time was at 2.5 yrs (we started late due to new sibling and moving), and we did a sticker chart and had him earn prizes. Each time he used the toilet he got a sticker, and after so many stickers he got a small toy (think dollar store!). We also used many potty training videos from the library and books. He loved these, and still sings the songs occasionally! Then he got the opportunity to earn a *big outing* (we went to Wiggly Town) if he stayed dry/clean for a week. After the big outing he slowly backtracked - not scared, but I think he just found it too inconvenient to stop playing. We tried to get him back on track, but after awhile we just gave up because it wasn't worth the contention and energy. We tried again at 3, but this time he only got stickers - we knew he could do it and wanted his motivation to be internal, and not for prizes. Again, he slowly backtracked. Our final attempt was at 3.5 yrs, and at this point it was a control issue. We had a talk about being a big boy, and I explained that he is responsible for using the toilet. We made it very inconvenient for him to have "accidents." He only got one pair of underwear for the day. If he went in his underwear he had to clean everything up (followed up by me later of course!), and then he had to wear a pull-up and wait in the laundry room while his underwear were washed and dried. It was all very matter-of-fact. No yelling, no lecturing, just "clean up your mess." Wonderful suggestion I got from Mamasource! If he had a true accident (tried to make it to the bathroom, but just missed, and was very upset) we forgave it and moved on. It only took 2 times sitting in the laundry room to keep him potty trained for good! If your little guy is truly scared, I would stick with an incentive system - stickers, jelly beans, M&Ms, whatever motivates your son. You may want to consider taking a break for a bit too - sometimes the pressure is too much and counterproductive. Either way, I would stay away from pull-ups during active potty training.