The amphibian and reptile fauna within a small area in a lowland rainforest fragment reserve in Amazonian Ecuador was intensively surveyed over an initial 2- year period via removal sampling (1986–88), coinciding with the construction of a road through the area and a subsequent surge of increased forest conversion and fragmentation in surrounding areas. A time-constrained transect sampling technique was employed to facilitate later, post-fragmentation visual-encounter monitoring to gather long-term data on species richness and composition (on a chronologically coarse scale). Between 1998 and 2005, an approximately equivalent quantity of sampling effort was accumulated in the same small area to compare with data from 1986–88, in an attempt to evaluate the efficacy of this reserve in conserving the herpetofaunal community documented more than 10 years earlier. Based on a total of 6,722 individual records obtained over 1,117 effort-hours of sampling divided into two primary and five secondary sampling periods, herpetofaunal species richness was among the highest yet reported from a single locality in Amazonia, with 84 amphibian and 82 reptile species recorded from 1986 through 2007. A complete species list is provided, with commentary on noteworthy records. Of 73 amphibian and 46 reptile species recorded in 1986–88 sampling, 68 amphibians (93%) and 40 reptiles (87%) were recorded again in sampling from 1998 through 2007; 11 amphibian and 33 reptile species not recorded in 1986–88 were added from 1998 to 2007. Pairwise comparisons of species composition among all sampling periods using a similarity index revealed a > 50% similarity for both taxonomic groups across all periods; similarity of the two primary periods (1986–88 vs. 1998–2005) was 0.90 for amphibians and 0.70 for reptiles. The present study provides another single-site reference point for the mega-diverse herpetofauna of the upper Amazon basin, but is distinct in offering long-term data on species persistence; results from the 20-year span of sampling suggest that this small reserve has, since 1986, successfully conserved this fauna. These results concur with previous long-term studies from the central Amazon basin in suggesting that relatively small reserves and other forest remnants with sufficient habitat diversity may substantially contribute to the continued survival of species-rich Amazon rainforest herpetofaunal communities amidst widespread regional deforestation.