Cryptachaea Archer 1946 currently contains 75 species. The genus is considered related to Achaearanea Strand 1929, Hentziectypus Archer 1946, and Parasteatoda Archer 1946 but differs from them in having a male palp with a short to medium embolus, which is not articulated and not supported on the back of the cymbium; the base is fused to the median apophysis, located in the hood of the cymbium. The Cryptachaea epigynum has uncoiled ducts leading to a pair of simple subcircular spermathecae. Twelve new species of Cryptachaea are here newly described from South America, seven from Brazil: Cryptachaea cidae new species from the state of Rio Grande do Sul; C. alleluia new species from Minas Gerais and Paraná; C. spectabilis new species from Paraná; C. divisor new species from the states of Amazonas, Acre, Rio de Janeiro, and Paraná; C. floresta new species from Amazonas; C. ericae new species and C. propinqua new species both from the state of Rio Grande do Sul. Cryptachaea catita new species occurs in Brazil and Argentina. Two new species are from Peru (C. tambopata new species and C. paquisha new species) and two are from Bolivia (C. benivia new species and C. lavia new species).