A series of 18 intravenous pyogenic granulomas (IVPG) was studied. The lesions were limited to the neck and upper extremity and appeared as nonspecific tumors. Most had a clinical duration of 2 months or less. Treatment was by excision and there were no recurrences. IVPG consists of an intraluminal polyp attached to the wall of the vein by a fibrovascular stalk. The characteristic appearance is of lobules of capillaries separated by a fibromyxoid stroma. The organization and histologic detail are similar to those of pyogenic granulomas that are uncomplicated by the changes of inflammation. Our observations suggest that IVPG develops in or adjacent to the wall of the involved vein. It probably receives its blood supply from a small artery that enters the lesion in the region of the stalk.