Kentropyx calcarata is a widely foraging teiid lizard species that inhabits forest environments east of the Andes in South America. We studied the ecology of a K. calcarata population in a remnant of Atlantic Forest in Brazil and evaluated lizards' body temperatures, stomach content, activity time, body measurements, and reproduction stage. We tested whether: 1) body temperature was influenced by substrate or air temperatures, 2) diet composition varied according to age and sex, and 3) there was sexual dimorphism in body size and bauplan (morphology). Lizards were more active during the hottest hours of the day, commonly in the litter or fallen logs. Body temperatures were influenced more by substrate temperatures than by air temperatures. Diet was composed mainly of arthropods, with Orthoptera and Araneae as the most important categories (numerically and volumetrically). Diet composition was similar between sexes, but varied ontogenetically as an effect of body size, with juveniles eating smaller prey than adults. Females were larger than males and there was difference in bauplan between sexes. We found reproductive males and females throughout the year. Kentropyx calcarata is ecologically similar to other species within the genus and the family, suggesting great importance of the evolutionary history for the ecology of this species.