Betel is a compound of natural substances chewed for its psychostimulating effects. Betel is composed of the nut of the areca palm (Areca catechu), the leaf of the betel pepper (Piper betle), and lime (calcium hydroxide). Approximately 200 million persons chew betel regularly throughout the western Pacific basin and south Asia. Only three drugs (nicotine, ethanol, and caffeine) are consumed more widely than betel. When betel is chewed, it produces mild psychoactive and cholinergic effects. There is copious production of a blood-red saliva that can stain oral structures. After years of chewing, the teeth may become red-brown to nearly black. Betel use is associated with oral leukoplakia, submucous fibrosis, and squamous cell carcinoma. Use of betel is discouraged in Western countries because of its alleged carcinogenic and perceived dysesthetic properties; nevertheless, betel is widely available in the West. (J Am Acad Dermatol 1997;37:81-8.)