To date, there are no comprehensive quantitative studies detailing the effect of vasectomy on the mouse testes. We examined the effects of vasectomy on testicular germ cell numbers using detailed light microscopy, and the effect of long-term vasectomy on sperm transport to the caput epididymis using radiolabelled germ cells. Short-term vasectomy has no significant effects on the number of germ cells within the testes; however, after long-term vasectomy, spermiogenesis was affected. Surprisingly, even after long-term vasectomy, the rate of spermatogenesis and sperm transport to the epididymis was unaffected.