Ten new species of Amphidraus Simon, 1900 from Brazil are described: A. belzonte sp. nov. (male), A. bifidus sp. nov. (male female), A. caxiuanan sp. nov. (male), A. draconicaudatus sp. nov. (male female), A. janauari sp. nov. (male), A. loxodontillus sp. nov. (male), A. mysticetus sp. nov. (male female), A. nigrigenu sp. nov. (male), A. pulvinus sp. nov. (male) and A. simplex sp. nov. (male female). A new diagnosis is proposed for the genus and three new combinations are established for species presently misplaced in Amphidraus: Titanattus parvus (Mello-Leitao, 1945) comb. nov., Truncattus manni (Bryant, 1943) comb. nov. and Truncattus mendicus (Bryant, 1943) comb. nov. Several new records for A. santanae Galiano, 1967 are provided, enabling brief comments on the morphological variations in this species.