Journal of Research in Medical Sciences1735-199511420061107Polycystic kidney and Down Syndrome278280ENAzarNickavarDepartment of Pediatrics, Iran University of Medical Sciences. anickavar@yahoo.com200602022006060120060516Kidney disease is not a common complication in Down Syndrome (DS). A variety of renal and urologic problems have been described in these patients and some develop renal failure. Coincidence of polycystic kidney disease and DS is a rare entity. This is a report of a 3.5-month-old infant with DS, known to have early end-stage renal failure due to polycystic kidney disease.