Osteochondromas rarely induce vascular complications by mechanical compression. We present the case of a subclavian artery pseudoaneursym caused by an osteochondroma of the scapula in a 67-year-old male. The diagnosis was based on a previous history of multiple exostoses, computed tomography and magnetic resonance imaging, as well as the local vascular clinical status of the lesion. Surgical treatment consisted of vascular and orthopaedic intervention. First, the vascular surgeon implanted a bypass of the subclavian artery from the ventral aspect, enabling the orthopaedic surgeon to resect the osteochondroma from the dorsal aspect. The patient recovered with full function. Vascular pseundoaneurysms should be taken into consideration in patients with osteochondromas, especially with a known history of multiple hereditary exostoses.