Background: Non-obstructive Azoospermia (NOA) is a common status among infertile men. The objective of the present study is to evaluate the efficacy of I.M administration of human chorionic gonadotropin (HCG) in men with NOA. Patients and methods: This study included a total of 50 with NOA who were administrated I.M injection of HCG 5000 I.U twice weekly for 3 months. The effect of HCG on spermatogenesis was assessed by the presence of motile sperms in the ejaculate in two semen sample. Results: The median of age was 39 (SD 11.37) years with the mean FSH of 28.16 (SD 16.44). Among 50 patients we found that sperms with a variable counts started to appear in semen of 25 patients which is statistically significant (p-value <0.001). Also, reduction of serum level of FSH was occurred to be 18.65 (SD 13.01) which is highly significant (p-value <0.001). Conclusion: Exogenous administration of HCG can improve spermatogenesis in patients with NOA and decrease level of FSH.