PIP: Many surgeons do not routinely warn patients of the possibility of late failure of vasectomy, either because they are unaware of this risk or do not want to create anxiety in their patients. However, the recent Thake case, in which a surgeon was found in breach of contract when late recanalization was followed by pregnancy, raises questions about this practice. A form a consent for sterilization that will meet the legal requirements of the National Health Service is currently in preparation. The consent form used for sterilization should be simple, including the patient's agreement to vasectomy, to anesthesia, and possibly to the delegation of the procedure to another surgeon. It should also refer to the small but possible risk of late return of fertility. Before the consent form is signed, the need for 2 consecutive negative sperm counts before contraceptive measures are abandoned and the limited success rate of sterilization reversal should be explained and a statement that these points have been dealt with should be signed by the patient and his wife and filed in the case record. In particular, the wife should be warned to report immediately any symptoms of pregnancy, no matter how long after the procedure. In addition, attention should be directed toward improving surgical techniques, especially tissue interposition. The most common cause of vasecomy failure is recanalization within the framework of the sheath of the vas. Late recanalization (after 2 zero sperm counts) has not been reported after tissue interposition, but numbers are too small for firm conclusion.