In the present note, we report for the first time the genus Microtityus Kjellesvig-Waering, 1966, from Puerto Rico, on the basis of two new species belonging to the subgenus Parvabsonus Armas, 1974. One of them occurs in the southwest of the main island and is morphologically most similar to Microtityus virginiae Armas, 1999, from Hispaniola, while the other occurs in a small satellite islet offshore the northeast coast and somewhat resembles Microtityus waeringi Francke & Sissom, 1980, from the Virgin Islands.