Introduction : In a climate changing world it is indispensable to know the behavioral and physiological responses of amphibians to environmental temperature variation. Even so, thermal ecology is unknown for many species, including Craugastor stejnegerianus . Therefore, it is important to describe the patterns and mechanisms that in uence body temperature and if these obey to the environmental temperature or to thermoregulation actions. Objective : The aim of this paper is to describe the relationship between environmental and substrate temperatures, as well as the behavior and substrate use with the body temperature of C. stejnegerianus . Methodology : The body temperature of individuals of C. stejnegerianus was monitored 13.4 h, along with measures of environmental temperature, substrate use and behavior observations. Results : the results obtained were that the body temperature is related to the substrate temperature but it does not depend on the variations of environmental temperature nor behavior or substrate use. Conclusion : Based in our ndings we propose that the body temperature variation of this frog is circumstantial and there is not behavior of thermoregulation.