Aneurysmal bone cyst (ABC) is a benign expansile bone tumor without metastasis capability. Only 3-4% of ABCs occur in the hand and they mainly take place in metaphysis' of long bones like metacarpals or phalanges. Carpal ABCs have been reported as individual case reports in the literature due to rarity. A patient presented with pain in her right wrist. Magnetic resonance imaging revealed a well circumscribed one cm sized mass in the pisiform bone that resembled an aneurysmal bone cyst. Total pisiformectomy was performed. Treatment options are total excision or curettaging in ABCs. But rarity of these lesions may delay the diagnosis process for the inexperienced surgeon.