Microorganisms which belong to Chlamydophila sp and Chlamydia sp genus are intracellular pathogens with characteristic life cycle. In humans the most common infections are caused by Chlamydophila pneumoniae i Chlamydia trachomatis.These pathogens are mainly responsible for infections of upper respiratory tract, infections of urinary tract and conjunctivitis. They are also considered to take part in patophysiology of Atherosclerosis, nervous system diseases and exacerbation of chronic respiratory tract diseases.