Both my DC gave up naps around 18-20 months. What happened with DD was that she would take a great nap, but then it would take 8-9 hours of wake time for her to fall asleep, putting her at around 10 pm or later bedtime. She just started taking longer and longer to go to sleep, finally up to about 2 hours. I can barely stay up that late. So, she was sleeping from 10 pm-7 am, and a 1 1/2 hour nap, 10 1/2 hours total sleep. I tried everything else first, earlier naptime (She'd happily nurse for hours until she was ready to nap) earlier bedtime (same thing). Woke her up earlier- cranky beastie all day long. Then, she stopped napping for DH on days I worked. So, we decided to try it for a week. It was a rough week for me, but she did great. Bed at 7, sleeps until 8 or 9 in the morning, for a total of 13 or 14 hours, go figure. The first week, we sometimes had to put her to bed as early as 5:30 if she was overtired. Every so often now, if she wakes up early for some reason, I'll put her to bed at 6 or 6:30. I wouldn't do without the nap if you can't do a substantially earlier bedtime, though. Especially the first couple of weeks, it could be really early while his little system adjusts. Every kid is different, I think you just have to follow your instincts and know that you can deal with whatever happens. If it works out badly, change it. Good luck!