Comet assay Single cell electrophoresis assay (SCGE) is a very sensitive method to determine DNA damage caused by exposure to mutagenic and carcinogenic and environmental agents that effect couples infertility. The aim of project was to evaluate DNA damage in males couples of females with recurrent spontaneous abortions. Forty males couples of females with unexplained recurrent spontaneous abortions and 25 healthy fertile males (control group) were evaluated for semen quality by conventional semen parameters, and alkaline comet assay was applied for the two groups. The results showed that patients male couples of females with RSA had a significant higher DNA damage than in the control group. It was concluded that patients male couples of females with RSA had high score of comet assay which suffers from RSA.