Problem Chlamydia trachomatis is the most common sexually transmitted infection worldwide. While infection in females requires a Th1 response for clearance, such a response in males may disrupt the immune privileged nature of the male reproductive tract, potentially contributing to infertility. Method of study We investigated the role of IgA in protection against an intrapenile Chlamydia muridarum infection of C57BL / 6 and pIgR) / ) mice. Results Here, we show that the poly immunoglobulin receptor is the main pathway for IgA transport into the male reproductive tract. The high levels of IgA seen in prostatic fluid of wild-type mice correlate with reduction in chlamydial infection both in vitro and in vivo. Conclusion These findings indicate that a Chlamydia vaccine that induces neutralizing IgA in the prostate will aid in the protection against infection in males.