A pregnant female (crown-rump length of embryo 5 mm) was captured in a mist net set in a small banana grove on the south side of the Río Mico, El Recreo, 25 m, in the Caribbean lowlands, on 27 February 1968. This specimen provides the first record of the big yellow-eared bat from Nicaragua. The species was recently reported for the first time from Costa Rica (Gardner _et al._, 1970:721); it was characterized as uncommon in Panamá by Handley (1966b:767). The one Costa Rican locality of record also is in the Caribbean versant. Selected external and cranial measurements of our female are: total length, 58 mm; length of hind foot, 11 mm; length of ear, 16 mm; length of forearm, 36.2 mm; weight, 12.3 gms; greatest length of skull, 21.1 mm; condylobasal length, 18.4 mm; zygomatic breadth, 12.3 mm; mastoid breadth, 10.5 mm; breadth across canines, 4.6 mm; breadth of braincase, 9.4 mm; length of maxillary toothrow, 7.2 mm; length of mandibular c-m3, 7.8 mm. Vampyressa pusilla thyone Thomas, 1909 _Specimens._--_Boaco_: Santa Rosa, 17 km N, 15 km E Boaco, 300 m, 5. _Chontales_: 1 km N, 2.5 km W Villa Somoza, 330 m, 1. _Managua_: Hda. San José, 2. _Matagalpa_: 2 km N, 6 km E Esquipulas, 960 m, 2. The only previous record of occurrence for the small yellow-eared bat from Nicaragua is based on an adult female from Hda. La Cumplida, 670 m, Matagalpa (Starrett and de la Torre, 1964:60). Two individuals taken near Esquipulas in mid-March, a pregnant female (crown-rump length of embryo 16 mm) and a male (testes 4 mm), were captured in nets set across trails cut through secondary forest. The wind was quite strong in this area at the time of our visit and only a few other species of bats--_Glossophaga soricina_, _Artibeus jamaicensis_, _A. toltecus_, _A. phaeotis_, _Uroderma bilobatum_, _Sturnira lilium_, _Centurio senex_, and _Diphylla ecaudata_--were taken in the same nets. The specimens from Boaco and Chontales were captured over small streams bordered by gallery forest. Four females collected at Santa Rosa on 21 March were pregnant; each carried a single embryo that measured 5, 18, 21, and 30 mm in crown-rump length; a male taken on the same date had testes that measured 3 mm. Selected external and cranial measurements of two males, followed by the average (extremes in parentheses) of six females are: length of forearm, 31.1, 30.8, 30.8 (30.0-31.4) mm; greatest length of skull, 18.9, 18.9, 18.5 (18.1-18.8) mm; zygomatic breadth, 11.0, 11.0, 10.6 (10.4-10.9) mm; mastoid breadth, 9.5, 9.2, 9.2 (9.0-9.3) mm; length of maxillary toothrow, 6.1, 5.9, 5.9 (5.7-6.1) mm. Chiroderma villosum jesupi J. A. Allen, 1900 _Specimens._--_Chinandega_: 6.5 km N, 1 km E Cosigüina, 10 m, 2; 4.5 km N Cosigüina, 15 m, 7; Hda. Bellavista, 720 m, Volcán Casita, 5; San Antonio, 35 m, 2. _Rivas_: 2 km N, 3 km E Mérida, 200 m, Isla de Ometepe, 1.