Latrodectism, the clinical syndrome that follows envenomation by the black widow spider, may easily be confused with more common conditions. Acute manifestations are characterized by agonizing pain and muscle spasm. Prolonged symptoms, primarily related to neurologic dysfunction, may occur. Familiarity with the manifestations of latrodectism is the key to diagnosis. Family physicians should consider latrodectism in patients presenting with severe pain and muscle cramps, particularly if the setting and history are consistent with a possible spider bite. Optimal therapy remains controversial. Early use of specific antivenin in severely envenomated patients may prevent the development of lingering symptoms, usually related to neurologic dysfunction.