Spiders are a ubiquitous component of the fauna of North America. At least 50 to 60 species in the United States are known to bite humans, although in most cases, the diagnosis is never suspected nor is treatment necessary. A few species of spiders are capable of causing necrotic wounds and, occasionally, death. This review is intended to provide an overview of the recent advances in the diagnosis and treatment of spider bites, as well as a compilation of the many species of spiders that have been reported to give clinically important bites.