Qualitative and quantitative studies were made on reptiles and amphibians in forests of two climatic zones in Panama, designated as the "Seasonally Humid Zone" and the "Perhumid Zone." Distribution and abundance of the lizard, Gonatodes albogularis fuscus, seemed to be influenced more by the structural configuration of the environment than by microclimatic conditions. Densities of this species were closely related to density of trees with scaly bark. It also occupies similar geometric configurations (broad vertical surfaces with crevices) in nonforested areas. By contrast, densities of the lizard, Anolis limifrons, in different forests did not correlate with density of structural features with which they had been previously shown to be associated. Fenced quadrats indicated that the herpetofauna of the lower forest strata consisted of one or two extremely abundant species with a larger number of rare ones. These abundant species had densities comparable to those of common temperate ones. The breeding season of A. limifrons is less sharply defined in the Perhumid Zone than in the Seasonally Humid one, probably because of the more uniform distribution of rainfall in the former. The Seasonally Humid Zone contains fewer species than the Perhumid one, largely due to a reduction in number of frogs.