The state of immunity in children with chronic calculous pyelonephritis before and after surgery is described. This form of the disease was observed in 88 patients, including 66 (75%) boys and 22 (25%) girls, 63 (71.5%) had bilateral kidney damage, and 25 (18%) had unilateral kidney damage. The immune status of children with chronic calculous pyelonephritis (CCP) was determined before, on the 7th and 14th day after surgery and during examinations 3-6 months later. Immunoglobulins of the main 3 classes GAM, T-, B- and O-lymphocytes were determined. The indicators of humoral immunity indicate an insufficient "norm of reactions" on the part of JgG and JgA in response to the chronic inflammatory process in the urinary system. The revealed changes in the immune system in children with CCP before and after surgery indicate a positive result of surgical and subsequent complex conservative treatment of chronic calculous pyelonephritis (CCP), accompanied by persistent remission. The clinical diversity of symptoms was determined by the age characteristics of patients, the size of stones, their localization. Associated complications, functional capacity of the kidneys and concomitant diseases of the body at the time of examination.