Cross-dystopia is a rare type of congenital anomaly, characterized by a displacement of the kidney to the opposite side, as a result of which both of them are located on the same side and in about 85% of such cases, a fusion of the parenchyma of two kidneys can be observed. We have not found descriptions of cases from practice when an orthotopic cystic dysplastic kidney with a lack of function associated with the pathology of the ureterovesical segment (ureterocele) was fused with the lower pole of a cross-dystopian normally formed kidney in literature.The patient, 8 d.o., a preliminary diagnosis - agenesis of the right kidney, doubling of the left kidney, cystic dysplasia, doubled left kidney whiyh ureterohydronephrosis lower half and ureterocele. In order to restore the outflow of urine and function of the lower half of the presumably doubled left kidney, a cystourethroscopy was performed. In a typical place on the right there is a correctly formed ureteral orifice, ureterocele on the left, which occupies half volume of bladder. With a holmium laser, an artificial orifice was formed in the ureterocele in order to restore the urine passage. At 9 m.o., tomography urinary tract was performed - cross-dystopia of the right kidney with fusion of the lower pole with a cystic dysplastic orthotopic left kidney.Laparoscopic nephrureterectomy of a non-functioning orthotopic kidney was performed.The control examination indicate complete clinical remission and social adaptation of the patient after discharge. Cross-dystopia of the kidney with fusion with cystic dysplastic kidney and a formed ureterocele is a rare congenital anomaly that requires timely examination in a specialized clinic and drawing up an individual treatment plan. The surgical manual should be focused on a symptomatic urological problem with an emphasis on preserving kidney function.