**Abstract**

*Chlamydia pneumoniae* and *Chlamydia trachomatis* are significant human pathogens that affect people of all ages worldwide. *Chlamydia psittaci* is a cause of zoonosis, and birds are the reservoirs. All are diseases for which there is no effective vaccine. *C. pneumoniae* is responsible for respiratory tract infections but the majority of recent *C. pneumoniae* research has focused on the persistent infections associated with chronic diseases and has been considered a childhood infection with potential adult consequences. *C. trachomatis* is one of the most common sexually transmitted diseases (STDs), and the prevalence of the infection is particularly high among young people and adolescents. Prepubertal infection of *C. trachomatis* may be a warning sign for probable child sexual abuse (CSA). In addition to its role in genital diseases, trachoma is one of the world's leading preventable causes of blindness. *C. trachomatis* can also cause Lymphogranuloma venereum (LGV), a systemic, sexually transmitted disease characterized by genital ulceration and inguinal lymphadenopathy. This chapter aims to provide an overview of *Chlamydia* infections in childhood and summarize the epidemiology, clinical manifestations, and treatment.

**Keywords:** *Chlamydia* infections, *Chlamydia pneumonia*, *Chlamydia Trachomatis*, *Chlamydia Psittachi*, Children
