In the present paper, the taxonomic status of several Hispaniolan members of the genus Tityus C. L. Koch, 1966 is revised after examination of almost all primary types and abundant supplementary material. This resulted in six new synonymies, which involve both extant and fossil species. The extant taxa herein synonymized are Tityus anasilviae Armas et Abud, 2004 under Tityus ottenwalderi Armas, 1999, Tityus bahoruco Teruel et Armas, 2006 under Tityus crassimanus (Thorell, 1876), Tityus ebanoverde Armas, 1999 under Tityus elii Armas et Marcano, 1992, and Tityus septentrionalis Armas et Abud, 2004 under Tityus portoplatensis Armas et Marcano, 1992. The fossil taxa herein synonymized are Tityus azari Lourenço, 2013† and Tityus (Brazilotityus) hartkorni Lourenço, 2009†, both under Tityus geratus Santiago-Blay et Poinar, 1988†. Updated distribution maps are given for all extant senior synonyms.