I had the same problem. We tried to move my daughter to a big girl bed when she was around 2 1/2. It was like Houdini. We would time how long it took her to cry, get out of bed, open her door, and stand at the gate by her door and cry....like 3 minutes flat. Basically, she wasn't ready. No, ifs, ands or buts. So, then we gave it up and tried a few months later when I had to move her out because I was expecting. Based upon the advice of others, I did the "supernanny" thing. First, we put up side rails on her bed. Then during a nap, I put her in her bed and closed her door. I sat on the other side of the door and talked to her (but she couldn't see me, only hear me). She cried, but I tried to talk her through it. Finally, after about 15 minutes, she settled down. Our talking got less and less (on purpose, I would only interject every few minutes just to let her know that I was there). After about 20+ minutes it was quiet and I crawled away. After that, there was no going back to the crib. It's like potty training. Once you start, you have to continue. Well, that evening, we did the same thing and it only took about 10 minutes. Ever since then, she's been fine. Good luck to you. I hope this helps.