Chlamydia represent a ubiquitous and unique obligate intracellular organisms found in a range of hosts. Chlamydia trachomatis represents a serious human disease burden as both a common bacterial sexually transmitted infection and ocular infection that is responsible for the most common form of preventable blindness worldwide. The organisms have been typically difficult to investigate due to the obligate intracellular growth hampering many molecular technologies, and indeed these challenges remain to this day. However, Chlamydia has shown little evidence of garnering antibiotic resistance and in many infections is responsive to treatment. Yet, the highly prevalent state of chlamydial STI and treatment may have contributed to the increasing resistance in other common bacterial STIs and we may need to re-think chlamydial therapy in future. Further, infections in livestock and wildlife such as the koala present more challenges for treatment. This talk will review chlamydial pathogenesis across the spheres of infections, and discuss future approaches to chlamydia treatment.