This review provides the physician with a clinical approach to the diagnosis and management of spider bites. It examines the recent literature concerning management of bites causing dermonecrosis, secondary infection, neuromuscular damage, and allergic reactions.Using the key words "spider bites," "brown recluse spider bites," "necrotic arachnidism," "black widow spider bites," "latrodectism," and "Tegenaria agrestis (Hobo spider)," the MEDLINE files were researched for articles pertinent to the practicing physician. Texts related to spiders and spider bites were also consulted.At least 60 species of spiders have been implicated in human bites. Most cause bites of minimal medical importance, requiring little treatment. Some (brown recluse, Hobo spider) cause severe cutaneous and systemic reactions requiring intensive medical management. The black widow bite can cause severe neurologic problems requiring the use of antivenin. Spider bites are frequently difficult to diagnose because the spider is not seen at the time of the suspected bite. Such bites should be labeled arthropod bites, vector unknown.