A complex clinico-instrumental and immuno-microbiological examination of 433 reproductive age women was performed. The results show that a lingering and relapsing chlamydian infection in women with an exacerbation of a chronic inflammatory urogenital disease develops against the background of disturbances in the anti-infective resistance system (AIRS), and is characterized by combination of chlamydian infection with other sexually transmitted infections and the presence of dysbiosis. The immunological aspects of this process consist in almost a total absence of neutrophiles' ability to digest a bacterial antigen, and incompleteness of phagocytosis, in general. These changes may be connected with a low immunogenicity and intracellular parasitizing of chlamydiae, on the one hand, and with primary incompetence of the subjects' AIRS, on the other. From a microbiological point of view, this is manifested by complete combined urogenital and colon dysbiosis.