Testicular sperm can be obtained from patients with non-obstructive azoospermia. However, there is not enough evidence concerning whether fresh or frozen-thawed sperm is better for successful pregnancy. We retrospectively compared initial treatment results of intracytoplasmic sperm injection using fresh and frozen-thawed testicular sperm in our institution. From August 1997 to May 2006, a total of 27 cases including 18 cases using fresh sperm (269 oocytes) and 9 cases using frozen sperm (97 oocytes) were evaluated. In the fresh and frozen sperm groups 33.4 and 32.9%, respectively, developed good quality embryo. There was no significant difference between the two groups in successful pregnancy and birth rates.