The purpose of this paper is to present an overview of congenital hydronephrosis, the anatomical and pathophysiological basis of this condition, to present diagnostic and therapeutic possibilities and to describe the role of the nurse in the treatment of this disease. With an incidence of 11,5 in 10.000, congenital hydronephrosis is a relatively common disorder. Due to its progressive course and severe consequences for kidney function as well as a pssibly fatal outcome, this disorder can be considered a serious health problem. The paper presents the most common types of pyeloureteral juncture obstruction which can lead to hydronephrosis: abberant blood vessels, ureteral stenosis and valvulas, adhesion etc. The pathopysiology of both acute and chronic obstruction is also shown, as well as the conseyuences of increased hydrostatic pressure in the renal canalicular system. Furthermore, in view of their diagnostic revalance, an overview of the possible clinical presentations of pediatric hydronephrosis is given: from prenatal ultrasound finding to the infant presentating with lumbar pain, palpable abdominal mass and signs od uroinfection. Diagnostic methods such as ultrasonography, excretion urography, diuretic infusion urography, radioisotope renography, computed tomography, magnetic urography, percutaneous nephrostomy. Whitaker`s test and obstruction uropathy markers, have also been mentioned. Congenital hydronephrosis can be treated both by conservative and surgical managment. The indications for surgical precedure include: symptomatic pyeloureteral juncture obstruction, asymptomatic obstruction with reduced renal function, failure od conservative managment and persisting asymptomatic obstruction. There are several variants of surgical approach to the kidney and several methods of surgical removal of the obstruction, but most of the authors prefer the Anderson-Hynes pyeloplasty. The role of the nurse in the treatment of congenital hydronephrosis lies in preoperative preparation of the child, postoperative care and education of parents.