A vasectomy is a surgery that prevents a man from being able to make a woman pregnant. A doctor will make a tiny cut in the man's skin and then seal off the tubes that carry his sperm. This stops him from being able to make any babies. After the surgery, the man will still have all the other parts of his body and he will still be able to do all of the same things he was able to do before, but he will not be able to make a baby.