Oral mucositis directly attributable to antileukemia chemotherapy occurs in almost 20% of adults undergoing such treatment. Although the mucositis is self-limited when uncomplicated by infection, the attendant extreme discomfort may produce physical and psychologic obstructions to continued anticancer treatment. Because of the ever-present risk of serious infection, drug-induced stomatitis constitutes a threat to the patient that must be kept under constant surveillance and control.