A review of our experience of 916 cases ofpartial bilateral vasectomy performed under local anaesthesia at the University Hospital, Kuala Lumpur during the
period between January 1971 and June 1980 is presented. Minor post-operative complications occurred in 5.8% of cases with a low post-operative infection rate of 1.2%. In 35% ofpatients, persistence of non-motile sperms in the semen were seen after at least ten ejaculations in each instance. In four of these cases non-motile sperms continued to persist into the sixth month of follow-up even after at least 50 ejaculations in each instance.