ABSTRACT. Local diversity and infl uence of seasonality on amphibians and reptiles assemblages in the Reserva Extrativista Chico Mendes, Acre, Brazil. Despite the high richness of amphibians and reptiles known for the southwestern portion of the Brazilian Amazon, the knowledge of these is punctual and few studies have evaluated the temporal variations in the occurrence and abundance of species. The goals of this study were to present the amphibians and reptiles assemblages in a locality of the Chico Mendes Extractive Reserve, verify which climate variables infl uence the temporal fl uctuations in richness and abundance, and identify the main species of the amphibians and reptiles infl uenced by them. The study area is located in the Seringal Etelvi region, southwestern portion of the Reserve, municipality of Brasiléia, state of Acre. Data collection took place between October 2011 and September 2012, for 48 sampling days, using the methods of searches limited by time and pitfall traps. There were recorded 978 specimens of 31 amphibians and 54 reptiles. Higher richness and abundance of amphibians occurred during the rainy season, with the monthly abundance positively associated with the mean temperature. Only the abundance of reptiles was higher during the rainy period. However, both richness and abundance were positively associated with mean temperature. Four amphibians, Allobates gr. marchesianus, Hamptophryne boliviana (Parker, 1927), Boana geographica (Spix, 1824) and Rhinella marina (Linnaeus, 1758), and two reptiles, Kentropyx pelviceps Cope, 1868 and Norops fuscoauratus (D'Orbigny, 1837), had their monthly abundances positively associated with the mean temperature. The lizard Dactyloa punctata (Daudin, 1802) had the monthly abundance associated with precipitation. It was possible to verify the increase of richness and abundance of amphibians and reptiles during periods when the availability of resources is favorable for many species. Species can react diff erently to climatic variations, whereas others are sensitive to fl uctuations, others seem answer easily or not reduce their abundances in periods theoretically unfavorable.KEYWORDS. Richness, abundance, Southwestern Amazonia, seasonality, temporal variation.RESUMO. Apesar da elevada riqueza de anfíbios e répteis conhecida para a porção Sul-Ocidental da Amazônia brasileira, o conhecimento sobre estes é pontual e poucos estudos avaliaram as variações temporais na ocorrência e abundância das espécies. Os objetivos deste estudo foram descrever as taxocenoses de anfíbios e répteis em uma localidade da Reserva Extrativista Chico Mendes, verifi car quais variáveis climáticas infl uenciam as fl utuações temporais na riqueza e abundância e identifi car as principais espécies de anfíbios e répteis infl uenciadas por elas. A área de estudo está localizada na região do Seringal Etelvi, porção sudoeste da Reserva, município de Brasiléia, estado do Acre. A coleta de dados ocorreu entre outubro de 2011 e setembro de 2012, num total de 48 dias de amostragem, com os mét...