Chlamydia trachomatis, an intracellular pathogen, is the leading cause of preventable blindness and sexually transmitted infections in the world. Infection of epithelial cells with Chlamydia results in the production of antigen-specific IFN-gamma -secreting CD4+ and CD8+ T cells. IFN-gamma activates indoleamine 2,3-dioxygenase (IDO), an enzyme that degrades tryptophan in the host cell. This IDO mediated tryptophan starvation is known to activate genes for persistence in the Chlamydia, which renders antibiotics ineffectiveness against it. Tryptophan supplementation causes reactivation of Chlamydia from persistent into metabolically active forms and then the antibiotics easily eradicate these active forms of Chlamydia. Therefore treating the chronic Chlamydia infection with antibiotics and tryptophan together may lead to better clearance of Chlamydia infection, and may be a better therapeutic approach in the future.