We evaluated the in vitro fertilization (IVF) outcome in 54 cycles using cryopreserved/thawed semen from fertile donors. Controls were other IVF patients matched by time frame, female age, stimulation protocol, number of pre-embryos transferred, and absence of a male factor using freshly ejaculated normal semen samples. In the study group and controls, respectively, post-thaw swim-up motility was 83.1% and 89.5%; fertilization rate of preovulatory oocytes (91.8%, 95.7%) and ongoing pregnancy rate (PR) per transfer (21.1%, 25.0%) were similar. The excellent fertilization rate with frozen/thawed semen was achieved through high-concentration insemination (0.5 x 10(6) motile sperm/mL). With use of frozen/thawed samples from infertile men (normal and subfertile samples), PR was similar but fertilization rate was lower. Cryopreserved semen is a valuable option for infertile couples in IVF therapy.