Streptokinase is a thrombolytic agent used most commonly for the dissolution of thrombi obstructing coronary arteries during acute myocardial infarction (MI). Anaphylactic reactions induced by streptokinase occur rarely. We report the case of a patient with acute MI who developed anaphylaxis shortly after the initiation of an intravenous infusion of streptokinase. The patient became profoundly hypotensive and developed an erythematous rash that spread rapidly to cover most of his body. He required mechanical ventilation and the administration of epinephrine for blood pressure support, which succeeded after dopamine and norepinephrine had failed. Streptokinase-induced anaphylaxis is thought to be mediated by immunoglobulin E (IgE), and patients who develop this adverse reaction have been shown to have higher serum concentrations of IgE to streptokinase than those who do not. Epinephrine is the agent of choice for the management of hypotension associated with anaphylaxis. Little evidence exists to support the routine pretreatment of patients who are to receive streptokinase with corticosteroids and/or antihistamines. Streptokinase skin testing may be a useful and accurate means of identifying patients at risk for streptokinase-induced anaphylaxis. Further investigation is required to determine the appropriateness of skin testing in streptokinase therapy.