Background. Nephronophthisis and medullary cystic kidney disease complex refers to the genetic heterogeneous group of inherited tubulointerstital nephritis. Nephronophthisis comprises at last 3 clinical manifestations, has the autosomal recessive pattern of inheritance, appears early in life and is the most frequent inherited kidney disease that causes terminal renal failure in childhood, while medullary cystic kidney disease has the autosomal dominant pattern of inheritance, is less frequent, and terminal renal failure appears later in life. These two forms have similar clinical and morphological findings but extrarenal manifestations, the median ages of occurrence of terminal renal failure, and siblings presence help us distinguish these diseases. Case report. In this article we illustrated the case of a 20- years old patient with the suspicion of having complex nephornophthisis and medullary cystic kidney disease based upon mild renal failure, seen in routinely taken laboratory findings and bilateral cysts in corticomedullary region of the kidneys verified on abdominal ultrasound examination. Conclusion. This disease should rise suspicion in children or adolescents with progressive renal failure, a typical clinical manifestation, blood and urine samples results, bilateral cysts in the corticomedullary region of the kidneys seen during ultrasound examination of the kidneys and family inheritance.