Q: Will push ups get rid of man boobs?

A: Pushups are a good chest exercise if you don't have access to gym equipment, but again by themselves they won't do a whole lot. It's impossible to lose fat in just one part of the body, be it chest or stomach or anything else. In order to lose fat on your chest, you need to lose fat overall. The most effective way of doing it is a fat-burning diet as described in the Nutrition article plus whole-body weight training. Pushups will train less than 20% of your body while you need to weight train as much of your body as possible to maximize fat burning.

So yes, do pushups, especially if you don't have access to a gym, but don't expect great results unless you also diet and weight train the rest of your body. Also check out http://www.mikesfitness.com/content/upper-chest-exercises-without-gym-eq... for more tips on pushups.