Mondor's disease is a superficial thrombophlebitis of anterolateral chest wall. The exact cause is unclear, but it is suggested that Mondor's disease is often associated with recent local trauma, muscular strain, or breast surgery. We report two cases with Mondor's disease who had malignant lymphoma. The coagulation profile was normal in both patients. The nodule involuted with analgesics within several months. The possibility of Mondor's disease associated with hypercoagulable state from malignancy may be suggested.