Kienböck disease is a pathology that remains uncommon in children, therefore the number of published cases of Kienböck's disease before skeletal maturity is limited. The etiology of Kienböck's disease is still controversial. Although many therapeutic methods are described in the literature. There is no consensus treatment for this pathology. We describe a case of Kienböck's disease of an 11-year-old girl who presented with avascular necrosis of the lunate bone confirmed by the radiologic pattern. And who was treated with 10 weeks of splinting with satisfying clinical outcome. Wrist pain and other symptoms resolved after 2 months. A magnetic resonance imaging (MRI) confirmed partial revascularization of the lunate. After 18 months of follow-up the patient remains asymptomatic.