Annotation. In almost 25% of patients, their progression continues, which leads to a change in the quality of life. Target . To evaluate the features of clinical and laboratory parameters in various forms of pyelonephritis in children. Material and research methods. During the study, 70 children with pyelonephritis were examined. All children were divided into two groups: group 1 consisted of 25 (35.7%) children with acute pyelonephritis, and the second group - 45 (64.3%) children with chronic pyelonephritis. Research results. The clinic of rPN in 100% of cases (19) manifested itself on the 3rd - 4th day of exposure to the etiological factor. Signs of intoxication prevailed (headache, lethargy, drowsiness, loss of appetite) - 78.9% (15/19), short-term subfebrile fever - 63.1% (12/19), recurrent abdominal pain - 47.3%) (9/19). Findings. The predominance of the secondary form of pyelonephritis was stated.