Bleomycin is a frequently used antitumor agent with adverse effects usually involving the lungs, skin, and bone marrow. An acute hyperpyrexic reaction has also been noted with this agent, usually after the initial injection. Thus a test dose is recommended before therapy is begun. A case of fulminant hyperpyrexia and death in a patient with lymphoma who had previously received multiple courses of bleomycin without prior hyperpyrexia is reported. Fever was associated with the patient's lymphoma and may have effectively reduced the patient's "margin" for tolerating the additional drug-induced pyrexia. It is suggested that attempts be made to lower fevers before therapy with this agent is initiated.