**Abstract**

Sexually transmitted infections (STIs) are a major health problem with an estimated burden of disease transmission as high as one million new cases per day globally. *Chlamydia trachomatis,* a member of the genus *Chlamydia*, is one of the most common and curable causative agents of STIs. *C. trochomatis* infections usually affect sexually active young adults and adolescents; and are composed of a broad spectrum of diseases varying from asymptomatic infection to severe genito-urinary infection leading to infertility and acute or chronic ocular infection (trachoma), which may result in blindness and pneumonia. Among the members of the genus *Chlamydia,* there are also two pathogenic species, *Chlamydia pneumoniae* and C*hlamydia psittaci* which are responsible for acute respiratory tract infections and febrile illness in humans. The incidence, pathophysiology, and diagnostic methods are discussed in detail in the previous chapters. The purpose of this chapter is to elucidate the management of infections due to *C. trachomatis, C. pneumoniae,* and *C. psittaci* including antibiotic susceptibility and resistance mechanisms, treatment recommendations for ocular infections, genito-urinary and respiratory tract infections, and management of sex partners, pregnant women, neonates, and children according to the latest data.

**Keywords:** *Chlamydia trachomatis*, *C. pneumoniae*, *C. psittaci*, chlamydial infection, antibiotic treatment
