Objective: To determine and compare the immunolocalization of functionally important antigens in human spermatozoa in an unexplained infertility (UI) group. Materials and Methods: In this study, the sperm samples of 20 patients undergoing evaluation belonging to normozoospermic group, whose primary reason of infertility was under investigation for this purpose, were screened. CD46, CD55 and CD52, CD69, CD98, fMLP, HI307, and 80280 were stained on the spermatozoa through indirect immunofluorescence technique. Results: In addition to CD46, CD55, and CD52 antigens, which are known to be localized on human spermatozoa, significant immunolocalization of several novel antigens including: CD52, CD69, CD98, fMLP, HI307, and 80280 were determined on the spermatozoa of the unexplained infertility group, possibly reflecting important roles in the pathophysiology of such unresolved clinical situations. Conclusion: Identification and characterization of antigens present on sperm cells is crucial for understanding of the diagnosis and treatment of unexplained infertility. Further studies were conducted to evaluate a possible correlation between the expression of these antigens and clinical outcomes in different well-defined infertility groups.