Vasectomy, or vasoligation, is an elective surgical procedure for male sterilization or permanent contraception. During the procedure, the male vasa deferentia are cut and tied or sealed so as to prevent sperm from entering into the urethra and thereby prevent fertilization of a female through sexual intercourse. Vasectomies are usually performed in a physician's office, medical clinic, or, when performed on an animal, in a veterinary clinic. Hospitalization is not normally required as the procedure is not complicated, the incisions are small, and the necessary equipment routine.

There are several methods by which a surgeon might complete a vasectomy procedure, all of which occlude (i.e., "seal") at least one side of each vas deferens. To help reduce anxiety and increase patient comfort, those who have an aversion to needles may consider a "no-needle" application of anesthesia while the 'no-scalpel' or 'open-ended' techniques help to accelerate recovery times and increase the chance of healthy recovery.

Due to the simplicity of the surgery, a vasectomy usually takes less than 30 minutes to complete. After a short recovery at the doctor's office (usually less than an hour), the patient is sent home to rest. Because the procedure is minimally invasive, many vasectomy patients find that they can resume their typical sexual behavior within a week, and do so with little or no discomfort.

Because the procedure is considered a permanent method of contraception and is not easily reversed, patients are usually counseled and advised to consider how the long-term outcome of a vasectomy might affect them both emotionally and physically. The procedure is not often encouraged for young single childless people as their risk of later regret is higher as chances of biological parenthood are thereby permanently reduced, often completely.