Hydatid disease of the kidney is rare and constitutes only 2 to 4% of all cases of hydatid. Its occurrence in children is even more rare. It ranks third after liver and lung. In the urinary tract, kidneys are generally affected, usually together with multiple organ involvement. An isolated renal hydatid cyst of the kidney without other organ involvement is very rare. We hereby present a case of pure hydatid cyst of the left kidney in a child presenting with left flank swelling and renal colic. She also had episodes of fever on and off for 2 months. On the basis of imaging studies, a diagnosis of hydatid cyst of the left kidney was established. The patient was successfully managed by simple nephrectomy. The patient is doing well at an 8-month follow-up.