Scalp arteriovenous malformations (AVMs) and sinus pericranii are two rare vascular lesions of the scalp that are part of the differential diagnosis in patients with scalp masses. The necessity of treatment of sinus pericranii, due to its risk of catastrophic hemorrhage or scalp necrosis, makes its diagnosis imperative. There are several theories on the pathogenesis of sinus pericranii with some of them stressing the importance of altered hemodynamic parameters in the affected area. An 8-year-old girl presented with a five centimeter soft, reducible scalp mass that had been present since birth. Clinical and radiographic evaluation revealed a sinus pericranii in association with a scalp AVM. She underwent resection of the sinus pericranii followed by embolization and planned separate en bloc resection of the AVM. During resection of the scalp AVM at a later date, the sinus pericranii was noted to have recurred. Concurrent treatment of all vascular anomalies associated with a sinus pericranii appears to be the key to its complete eradication.