Microsurgical epididymal sperm aspiration (MESA), or sperm microaspiration retrieval technique (SMART), in conjunction with in vitro fertilization is a successful therapy in male infertility. From November 1991 to March 1994 a total of 29 attempts at MESA with subsequent IVF were made. Of 48 aspirations, 37 were successful and 13 attempts at IVF were possible, 6 of which were successful with 10 subsequent embryo transfers. In all, 3 pregnancies were achieved and 1 boy was born. In conclusion, microsurgical spermaspiration in conjunction with in vitro fertilization is a way of treating male infertility with a chance of achieving paternity with the partner's own sperm; the chances are probably better with intracytoplasmatic sperm injection.