Complete excision of cutaneous angiosarcoma, which is a rare, vascular, and aggressive tumor, is challenging. Its multifocal nature and propensity for lateral spread make the gross assessment of surgical margins difficult. Neither the use of frozen section analysis nor Mohs surgery consistently improves the probability of margin-free excision. Recent studies have advocated the use of indocyanine green to evaluate the vascular system perioperatively. We describe the intraoperative use of indocyanine green to help define the excision margin of a locally extensive scalp angiosarcoma in an elderly man.