The records of Aberdeen men requesting vasectomy between 1978 and 1981 were studied and a sample of men were interviewed about 3 years after the operation; 85% completed the standard requirements for seminal analysis and were given the "all clear"; two-thirds were cleared after sending 2 samples and usually within 20 weeks after vasectomy; 10% of men sent at least 1 sample but were never cleared and the remaining 5% ignored the requirements. Information from 70 men (63 interviews, 7 questionnaires) gave some indication of reasons, often multiple, for incomplete or non-compliance; these included embarrassment, ambiguous feelings about having more children, inadequate understanding of reproductive physiology and blind faith in the surgeon.