We successfully produced offspring of old male BDF1 mice using in vitro fertilization. Although 7 old male mice (33 months of age) were infertile and revealed frequent degeneration in the seminiferous epithelia, 4 of them had spermatozoa in the caudae epididymides. The IVF rate of their sperm with eggs from young ICR mice was very high (82.0%). The production rate of offspring was also satisfactory (61.6%). The present study indicates that the IVF method is useful for producing offspring of aged male mice.