-Observations on habitat preference, roosting behavior, relative abundance, and distribution are reported for 14 species of Jamaican bats. In addition, data on the condition of the reproductive organs and on sex ratios during December and January are presented. Included in the list of species are the two rare and poorly known bats, Phyllonycteris aphylla and Natalus major jamaicensis. Jamaica possesses a relatively rich insular bat fauna including a few interesting endemics, which are poorly known. Allen (1911) listed 19 species from the island. Since then, five others have been reported. In addition, two species, Tonatia saurophila and Brachyphylla pumila, have been described from cave deposits (Koopman and Williams, 1951). These probably represent extinct taxa inasmuch as living representatives of these genera have not been found in Jamaica. The literature of this fauna is generally meager and virtually nothing has appeared dealing with the ecology of Jamaican bats; thus, it seems desirable to present data on 14 species observed and collected by the author with the assistance of a group of students from Colgate University. A total of 12 weeks was spent in the field during December and January of 1965, 1966, and 1967. During these periods 21 caves were investigated of which 13 were found to be inhabited by bats. In addition, some effort was made to locate bats in habitats other than caves. Financial support for the study was obtained from Colgate University and in 1966 by grant GY-231 of the National Science Foundation. In the following treatment of species, only those collected during the course of this study are listed. All measurements are in millimeters. Locations of the caves mentioned in the paper are given below. Sewell Cave, St. James Parish, in the southeast corner of the city of Montego Bay. Windsor Great Cave, Trelawney Parish, 4 mi. SW Sherwood Content. Oxford Cave, Manchester Parish, near Auchtembeddie. Claremont Cave, St. Ann Parish, 1 mi. N Claremont. Moseley Hall Cave, St. Ann Parish, near Moseley Hall (Blackstonedge Post Office). Mount Plenty Cave, St. Ann Parish, 1 mi. N Goshen. Sans Souci Grotto, St. Mary Parish, 4 mi. E Ocho Rios. Unnamed sea cave in St. Mary Parish, 4 mi. E Oracabessa. St. Clair Cave, St. Catherine Parish, 3 mi. S Ewarton. Worthy Park no. 1 Cave, St. Catherine Parish, 2 mi. E Worthy Park. Portland (Ridge) Cave, Clarendon Parish, 2 mi. W Mahoe Gardens. Grove Cave, Portland Parish, 2 mi. SW Sherwood Forest. Ferry Cave, St. Andrew Parish, near the village of Ferry between Kingston and Spanish Town.