List of medically significant spider bites

A number of spiders can cause spider bites that are medically important. Almost all spiders produce venom but only a few are classified as "venomous" and able to cause significant harm to humans. Two medically important spider genera have a worldwide distribution—Latrodectus and Loxosceles. Others have a limited distribution.

Medical reports have been criticized for poor evidence. In the last century, both white tailed and wolf spiders were considered medically significant, only to be recanted. Only eight genera (Phoneutria, Atrax, Latrodectus, Loxosceles, Sicarius, Hexophthalma, Hadronyche and Missulena) are considered medically significant. Bites of these spiders have a range of severity, with only a minority having severe symptoms. Deaths by verified spider bites are exceedingly rare (e.g. one in Australia in 37 years).