The Neotropical "club-tailed" scorpions of the genus Rhopalurus Thorell, 1876, and two related genera in family Buthidae C.L. Koch, 1837, i.e., Physoctonus Mello-Leitão, 1934, and Troglorhopalurus Lourenço et al., 2004, are revised, based on a simultaneous phylogenetic analysis of 90 morphological characters and 4260 aligned DNA nucleotides from three mitochondrial and two nuclear gene loci. The monophyletic New World buthid subfamily Rhopalurusinae Bucherl, 1971, to which these scorpions were originally assigned, is redefined, revised diagnoses and a key to identification of its genera and species (except for Centruroides Marx, 1890) provided, and their distributions mapped. The paraphyly of Rhopalurus Thorell, 1876, which comprises several monophyletic groups congruent with its disjunct distribution, justifies its relimitation and that of Troglorhopalurus Lourenço et al., 2004, the revalidation of Heteroctenus Pocock, 1893, and creation of Ischnotelson, gen. nov. (type species: Rhopalurus guanambiensis Lenarducci, Pinto-da-Rocha and Lucas, 2005) and Jaguajir, gen. nov. (type species: Rhopalurus agamemnon C.L. Koch, 1839). Ten new combinations are proposed.