Bats were collected in Belize, Central America during the summers of 1972, 73, 75, and 76. A variety of collecting techniques were utilized but most success was obtained with mist nets and capturing by hand at roostsites. The majority of the bats were collected between 15 June and 12 July on Glenwood Farm located on the Sibun River, Belize District, Belize (17017' N, 88°33' W)A total of 108 bats including 13 species representing 5 families was collected on Glenwood Farm. In the family Emballonuridae three species, R'gvnchonycteris naso,,Saccouteryx,bilineata, and Balantio-oteryx io, were collected. The six species belonging to the family Phyllostomatidae Glossophaga,soriciria, Carollia brevicauda,, Carollia, perspicillata,, Sturnira lilium, Artibeus phaeotis, Artibeus lituratus.. Desmodus rotundus was the only member of the family Desmodontidae collected. In the family Vesroertilionidae two species, Myotis,keaysi and Eptesi.cus,furinalis,, were collected. Only one species of the family Nolossidae, Molossus,molcasus, was collected.Eighteen bats of five species were collected in mist nets. All but one of these species, D. rotundus, were frugivorous. An additional 90 bats of 7 species were collected at various roostsites, two caves, a fig tree, and the farmhouse. All but one of these bat species were insectivorous. The exception was G. soricina, a frugivorous species, which was the only species represented in both the mist net and the roostsite samples. Collected specimens had a sex ratio of 68 males to 40 females or 1 male:0.6 female. Classified by age they represented 83 adults (55 males, 28 females) and 25 juveniles (13 males, 12 females).Body and skull measurements were taken from the adults. Ectoparasites were removed and identified. The reproductive morphology and histology were described for all specimens. The reproductive condition of species was discussed. In addition, published data on Neotropi-cal bat reproduction were compiled and correlated to determine annual patterns for the various species and families.The influence of phylogenetic relationships, food habits, climate, and vegetation were considered in the discussion of the reproductive patterns exhibited by the various species collected. The reproductive patterns identified in this study were monestrous and seasonal polyestrous.Adult specimens of all species collected between 15 June and 12 July showed signs of reproductive activity. The monestrous pattern, having one estrus per year, was found in the insectivorous S. bilineata and M. molossus. A seasonal polyestrous pattern, having more than one estrus per year with a definite anestrus period, was found in the insectivorous B. io and the frugivorous G. soricina and C. brevicauda.of each species was discussed. In additon to the G. soricina collected on Glenwood Farm, 10 adult females were collected in a small cave near Augustine, Cayo District. Three of these females were lactating but none were pregnant. Of eight specimens examined, five had multiovular follicles in one or both ovaries. Biovular, triovular, and tetraovular follicles were present. One binucleated oocyte was present indicating that the probable source of the multiovular follicles was due to an abnormal mitotic division of the oocyte.A complete maternal colony of M. malossus individuals was captured in the attic of the farmhouse on Glenwood Farm. The colony consisted of an adult male, 10 lactating females, 1 subadult male, 4 juvenile males, and 5 juvenile females. A colony of adult males was discovered in one corner of the farmhouse only a short distance away from the maternal colony.New records of bat species for the country of Belize include: B. io, Peropteryx,kanpleri (family Mormoopidae), and R. tumida,(family Vespertilionidae). A single P. kappleri,female was taken from a small cave near Augustine, Cayo District. A R. tumida female was collected in an insect sweepnet at Blancaneaux Dodge, Cayo District, and two pregnant females were collected at Mile 30, Western Highway, Belize District. The latter were taken from a hollow tree stump. These R. tumida specimens represent the first records of this species from the mainland of Belize.