We report a rare case of diaphragmatic hemangioma with computed tomography and magnetic resonance imaging findings. A routine chest radiograph in a 75-year-old woman revealed a nodular opacity in the right lower lung field. Multidetector-row computed tomography revealed a well-circumscribed nodule arising from the diaphragm or pleura. Dynamic magnetic resonance imaging of the nodule showed a pattern of gradually increasing signal intensity. On the basis of the intraoperative and histopathologic findings, venous hemangioma arising from the diaphragm was diagnosed.