Cystic renal disease is divided into two categories: non-hereditary and hereditary disease. The most common type of nonhereditary cystic renal disease is multicystic dysplastic kidney (MCDK). MCDK is a subtype of dysplastic kidney. Typical types of hereditary disease include autosomal recessive polycystic kidney disease (ARPKD) and autosomal dominant polycystic kidney disease (ADPKD). Defects in the structure or function of primary cilia may lead to the development of various cystic renal disease including ARPKD, ADPKD, juvenile nephronophthisis, and congenital nephrotic syndrome. In general, imaging starts with ultrasound. The ultrasonographic findings of MCDK include multicystic structure with big and some smaller cysts that do not communicate and possibly some central echogenic, nondifferentiated tissue components. In ARPKD, ultrasound shows bilaterally enlarged cysts with increased echogenicity of renal parenchyma and small cysts (<3 mm). Histology demonstrates a fusiform dilatation of the collecting ducts and ductal plated malformation at the level of the liver resulting in hepatic fibrosis and Caroli disease. ARPKD has mutations identified in the PKHD1 gene. ADPKD is a ciliopathy that affects not only the kidneys and liver but also the pancreas. ADPKD has mutations identified in the PKD1 and PKD2 genes. Ultrasound shows multiple renal cysts without kidney enlargement. Ultrasound is useful for diagnosis of cystic renal disease. Familial and clinical inquiry will further help towards the diagnosis.