Culebra, which is an archipelago that forms part of the Puerto Rican Bank, has had a limited scope of biological studies, provided the basis for this work. Culebra’s terrestrial resources were disturbed since the early 1900’s until the 1970’s. Since the 1970’s, a natural reserve, called the Culebra National Wildlife Refuge, has been managed by the United States Fish and Wildlife Service. The purpose of this research is to update the species list of reptiles and amphibians on the Island as well as to examine how spatial and temporal changes affect the diversity and abundance of its herpetofauna. Twenty species of reptiles and amphibians placed in thirteen families were identified. Two new records for Mount Resaca are Eleutherodactylus coqui Thomas, 1966 and Eleutherodactylus cochranae Grant, 1932. Meanwhile, Anolis pulchellus Duméril and Bibron, 1837 is a new record for the Luis Peña Cay. Mount Resaca has greater species richness, ten more species than the Luis Peña Cay, three species of amphibians and seven species of reptiles. The differences in herpetofaunal biodiversity (e.g. Shannon Wiener, Simpson’s Index and Margalef’s Index) between Mount Resaca and the Luis Peña Cay were statistically significant. Abiotic factors, such as temperature and humidity, and biotic factors, such as vegetation and the presence of other animal species, possibly influence the relative abundances within these communities.