The current study adds 23 new records to the previously described monogonot rotifers of Cozumel, increasing the number of reported species to 40; these species are grouped into two orders, 11 families and 18 genera. Littoral and limnetic samples from 17 aquatic systems were examined, including wet dolines, coastal lagoons, temporary pools and artificial systems (reservoirs). Of the 36 species found, the following organisms represent new findings for Cozumel: Anuraeopsis fissa, Brachionus angularis, B. rubens, B. plicatilis sensu lato, Beuchampiella eudactylota, Euchlanis dilatata, Mytilina bisulcata, Colurella adriatica, Lepadella ovalis, L. rhomboides, Squatinella mutica, Lecane aculeata, L. climacois, L. crepida, L. cornuta, L. grandis, L. obtusa, L. pyriformis, Cephalodella forficula, Scaridium bostjani, Trichocerca pusilla, Polyarthra cf. dolichoptera, P. vulgaris, Dicranophorus epicharis and Testudinella patina. Additional information is reported for these species.