The clinical use of low reactive level laser therapy (LLLT) has been reported in several aspects of bioactivation. This study reports an investigation into the possible application or LLLT for the treatment of male infertility. Four azoospermic and 16 oligospemiic male patients were treated with a 6mW He-Ne/2.5 mW pulsed GaAs diode laser with a dose of 1.3 J/cm². Although no improvement was noted in the azoespermic subjects, the sperm count increased from 2 to 5 times in the oligospermic subjects. In addition. ejaculation of abnormal spermatozoa decreased in several subjects. Libido also increased in 15 of the 20 patients. From these findings it was concluded that LLLT offers a possible treatment for the oligospermic patient. particularly for the subfertile.