This article describes a case of a 11-year-old boy with an osteochondroma of the peroneal head causing peroneal nerve palsy. Physical examination disclosed large exostoses palpated at the right fibular head. Neurological examination revealed paresis of the tibialis anterior, lateral peroneal, and extensor digitorum muscles with a muscle strength grade of 2. Electrophysiological studies confirmed denervation of the muscles supplied by the right peroneal nerve. Radiological examination showed an osteochondroma in the head of the right fibula. The patient underwent surgical decompression of the right peroneal nerve after resection of the bone tumor. At 36-month follow-up, there was a complete recovery of the deficits. Peroneal mononeuropathy in children is uncommon. Osteochondroma is a benign tumor consisting of projecting bone capped by cartilage. These tumors may be solitary or multiple and occur in hereditary multiple exostoses syndrome. The conjunction of this lesion with peroneal nerve palsy has been exceptionally reported for children, usually linked to hereditary multiple exostoses syndrome. Most peroneal nerve trauma occurs at the fibular head, where the common nerve has not yet divided into its deep and superficial peroneal nerve and where most peroneal nerve lesions, therefore, involve both branches, although motor deficits are more frequently involved than sensory ones. Surgical treatment should not be delayed because neurological improvement may be achieved if surgery is performed before severe neurological deficits become irreversible.