Hydatid cyst (HC) is a parasitic infection transmitted by oral ingestion of Echinococcus granulosus eggs. Isolated kidney involvement is extremely rare. It is even less common in children. We present a case of isolated renal HC in a 6-year-old boy from Şanlıurfa, southeast Turkey who complained of abdominal pain and distension. Cystectomy was performed with a flank incision using the extraperitoneal approach. No recurrence was detected in the postoperative 6-month follow-up. There are not enough data about the efficacy of medical treatment in renal HC. Therefore, medical treatment should be considered pre- and post-operatively to prevent dissemination, rather than being used as a primary treatment. Kidney-sparing surgery should be the first choice in patients with isolated renal HC. However, nephrectomy is recommended for nonfunctioning kidneys, large cysts thought to be connected with the collecting system, and cysts with suspicious tumor. In societies where HC disease is endemic, renal HC should be considered in children with cysts located in kidney, even if the indirect hemagglutination test is negative.