Introduction. Encrusted pyelitis is a rare clinical form of urolithiasis. It represents a formation of stones on the mucosa of collecting system because of violation of epithelial function. Encrusted pyelitis characterized by formation of multiple planar stones intimately soldered to the epithelial lining. Generally, accepted methods of surgical removal of stones is not effective in such case and different approach is required.

Clinical case. Presented a clinical case of successful treatment of patient with encrusted pyelitis by chemolytic therapy. It carried out by irrigating the collecting system with a solution injected through nephrostomy drain.

Discussion. Analysis of the literature on encrusted pyelitis shows that due to the rare occurrence of this pathology, there is no standardized approach to the treatment of this group of patients, and publications are limited to the analysis of clinical observations. A number of scientific papers confirmed effect of chemolytic therapy in these situations.

Conclusion. A patient with encrusted pyelitis underwent several courses of chemolytic therapy with good results. Stone free status is achieved. It is important to note that chemolysis was effective only in relation to those stones that were on the way of the irrigation solution from the supply nephrostomy tube to the discharge one.