The first pregnancy established after subzonal insertion of frozen-thawed sperm obtained from a patient with seminoma and severe oligoasthenospermia is reported. A total of 800,000 sperm with a poor progressive motility were recovered after thawing. Three to seven motile spermatozoa were injected into the perivitelline space of each of 10 oocytes, and seven sibling oocytes were coincubated and inseminated with 200,000 motile sperm/mL. Only 1 of the manipulated oocytes fertilized and was transferred to the uterus 65 hours after insemination at the eight-cell stage. A healthy boy weighing 3,600 g was delivered spontaneously at 38 weeks of pregnancy. This report gives hope to patients with testicular malignancy and severely impaired sperm function to maintain their reproductive potential through sperm banking and assisted fertilization techniques.