Of the 18 previously known Mangora species from South America, three names are synonyms and 12 species have their genitalia illustrated here for the first time. All of the 127 new species found are described, illustrated, and named. Most of these many species are found in the Amazon drainage. All the species outside the Amazon have only limited distributions except M. melanocephala, the most common Mangora, found between the Isthmus of Tehuantepec, Mexico, and northern Argentina. Only four species found in Central America extend their ranges to South America. A new method of immobilizing and examining palpi is described.