Vasectomy must be considered a permanent form of contraception. However, there is a very small failure rate where the two ends of the tube grow together again. This happens in about 1 in 1000 cases in the first four months and 1 in 5000 in the first 3 to 4 years.

The operation does not affect the ability of the man to perform sexual intercourse and does not affect sexual drive in any way. Seminal fluid will continue to be ejaculated when a man reaches a climax but it will not contain sperm. The testicles continue to produce the hormone which is responsible for masculine qualities. In other words, the operation does not affect a man's sexuality.