The arteries supplying the lips are very tortuous so they can accommodate the movements of the mouth. Labial arteries taper only slightly and are usually caliber-persistent vessels. On rare occasions, older adults have a tumor-like lesion form on the vermilion of the upper or lower lip or have an ulcer of the lower lip. Cancer is the concern of the person and his or her physician and dentist. In surgical excision of this tumor-like lesion or removal of a specimen for biopsy, the treatment team needs to prepare for the possibility of brisk arterial bleeding and have proper materials to ligate the labial artery in the event it is inadvertently transected. It is also important to remember that both ends of a transected artery should be ligated. Could the tumor-like lesion or lip ulcer be a mucosal sign of a caliber-persistent artery of another area of the gastrointestinal tract? This question has not received adequate investigation. The relationship is unlikely but deserves consideration. (J Am Acad Dermatol 2002;46:256-9.)