We studied the ecology of the lizard Cnemidophorus ocellifer Spix 1825 in the central Brazilian Cerrado. Cnemidophorus ocellifer was active on open ground, in sandy soils and rocky fields, during the hottest hours of the day. Mean body temperatures (37.5°C) were high, relative to sympatric lizard species, and more associated with substrate temperatures than with air temperatures. The thermal ecology of C. ocellifer seems to be tightly associated with an active mode of foraging. Termites were the most important prey, and there was no significant association between head dimensions and prey dimensions. Cnemidophorus ocellifer showed strong sexual dimorphism in body size and shape, with males having larger bodies and head dimensions, and females having longer and thicker bodies. Clutch size averaged 2.1 and was positively correlated with female SVL. Females were reproductively active during the dry season (May to September) and recruitment occurred from July to November. Males were reproductively active throughout the year, peaking from March to August, coinciding with the period of female reproduction. The reproductive cycle in C. ocellifer may be determined by the greater availability of direct sunlight and its physiological effects upon breeding activities, such as courtship and mating, during the dry season.