Protocol describes a method for vasectomy in which the vas deferens is accessed through the abdominal wall. Mice are ready for mating after ~10-14 days. Vasectomized males can be bred with fertile females to obtain plugs for timed matings. The pseudopregnant females can then be used for oviduct and uterine transfers. For an alternative protocol, see Vasectomy for Generation of Sterile Males: Access via Scrotal Sac.