Objectives: With the adventure of intracytoplasmic sperm injection (ICSI) technique, great progresses have developed in the treatment of infertility. Concentration on the properties of male's gamete has been encouraged by the increasing concerns about the causes of ICSI failure. We hence conducted this study to investigate the probable association of sperm parameters with ISCI outcome. Methods: A total of 523 couples referred to Isfahan Fertility and Sterility Center from January 2007 to June 2008 for ICSI. Semen analysis was performed before ICSI procedure according to the WHO criteria. Patients were assigned into successful ICSI (case) and failed ICSI (control) groups. Sperm parameters were then compared between the 2 groups. Results: One hundred and six patients (20%) had successful ICSI results (case group) compared with 417 couples (80%) with undesirable ICSI outcomes (control group). Among evaluated factors, sperm agglutination (p = 0.007), sperm concentration (p = 0.043), leukocytospermia (p = 0.026) and head abnormality of sperm (p = 0.019) showed statistically significant differences between two groups with differing ICSI results. None of the other semen parameters revealed significant differences between these two groups. Conclusion: Our study showed that some sperm parameters are associated with desirable ICSI outcome. However, it is unclear whether these associations are causal.