Arsenic poisoning continues to require awareness of its diverse clinical manifestations. Industry is the major source of arsenic exposure. Although epidemiologic studies strongly contend that arsenic is carcinogenic, there are little supportive research data. Arsenic poisoning, both acute and chronic, is often overlooked initially in the evaluation of the patient with multisystem disease, but once it is suspected, many accurate methods are available to quantitate the amount and duration of exposure. Treatment with dimercaprol remains the mainstay of therapy, and early treatment is necessary to prevent irreversible complications.