This species of Alboleptonia was previously known only from Cuba. It can be distinguished by the white, non-hygrophanous pileus, elongate angular spores, lack of cheilocystidia, and presence of caulocystidia. Also, the odor of fresh basidiomata is distinctly foetid to alliaceous. The specimens shown here were collected by T. J. Baroni near the “La Casona,” in the Guanacaste Conservation Area in NW Costa Rica. A key to Greater Antillean taxa can be found in Mycologia 90: 680-696. 1998. An online version is at the Basidiomycetes of the Greater Antilles site.