Hemangiopericytomas, first described in 1942, are rare, highly vascular neoplasms that arise from capillary pericytes. They are seen most commonly as a painless mass arising from the lower extremity but can also originate in the pelvic retroperitoneum and on the head, neck, chest, and abdomen. An unusual case is reported here of a patient presenting with recurrent massive upper gastrointestinal (GI) bleeding in whom a large hemangiopericytoma was found arising in the perisplenic soft tissues. Precedence exists in the literature for the association of hemangiopericytoma with GI bleeding. In prior reports, however, a mural origin of the tumor and subsequent bleeding into the GI lumen was demonstrated. In the case presented here, marked dilatation of the gastric and splenic vessels was noted, but there was no direct pathologic involvement of the stomach wall. It is proposed that superficial gastric erosions combined with the tumor-associated increased vascularity within the stomach wall led to recurrent major bleeding. Diagnosis of these tumors roentgenographically is nonspecific, but angiography is helpful. Morphological characteristics allow accurate histopathological diagnosis and provide prognostic information. The treatment of choice remains wide surgical excision, with the addition of radiation or chemotherapy in selected cases.