The present study is the fourth of a series dealing with the Brazilian Scytodidae fauna and emphasizes the Atlantic Forest species. Nevertheless, other undescribed species from different biomes were also included, in order to supply as much knowledge possible on the Neotropical Scytodidae fauna. Thirty two species are newly described: Scytodes tapacura n. sp., S. itabaiana n. sp., S. saaristoi n. sp., S. una n. sp. and S. guapiassu n. sp., S. maromba n. sp., S. tyaia n. sp., S. jurubatuba n. sp., S. bocaina n. sp., S. genebra n. sp., S. itapecerica n. sp., S. antonina n. sp. and S. chopim n. sp., S. pintodarochai n. sp., S. ytu n. sp., S. tabuleiro n. sp., S. maquine n. sp., S. chapeco n. sp., S. imbituba n. sp., S. ilhota n. sp. and S. turvo n. sp. from the Atlantic Forest, S. tapuia n. sp., S. adisi n. sp., S. mangabeiras n. sp., S. marlieria n. sp., S. nambiobyrassu n. sp. and S. vassununga n. sp., from Cerrado (Brazilian savannah), S. sincora n. sp., from Caatinga, S. caratinga n. sp., S. domhelvecio n. sp., S. brignolii n. sp. and S. bonito n. sp., from transition areas between Cerrado and Atlantic Forest. In addition, Scytodes lineatipes Taczanowski is considered a senior synonym of S. romitii Caporiacco. With this paper the number of native Brazilian species of Scytodes is increased from 41 to 73, representing almost 40% of the Scytodes fauna of the world.