Pilomatricoma is a relatively rare tumor of the skin derived from primitive basal cells of the epidermis that differentiate into hair matrix cells. These tumors appear as solitary, firm nodules, showing a normal to pearl white epidermis. Its most frequent locations are the head and neck, while involvement of the upper extremities is relatively uncommon. Herein, we present the case of a seventeen-year-old female with pilomatricoma of the arm and review the literature regarding pilomatricomas of the upper extremities. The diagnosis of pilomatricoma is confirmed histologically and its treatment is based on surgical excision. Because of the low incidence and variable clinical presentation, pilomatricoma is a tumor not commonly suspected preoperatively. This presentation may help clinicians to diagnose this entity more effectively and decrease the rate of misdiagnosis.