Introduction: Considering that the elevated plus maze (EPM) for rodents is, actually, the anxiety model more used in the world, and that, the rat behavior in this model is much vulnerable to multiple variables, the current work studied the behavioral effects of two feeding schedules on rat behavior (males and females), evaluating the variables discrimination capacity and possible confusion variables. Materials and methods: Were evaluated 31 animals of both genders and the same age. Since 21 post-natal day, one group per gender received food during the morning and another group, during the afternoon. The animals were individually exposed to the EPM during 5 minutes between 8 and 12 in the morning. The sessions, were filmed and processed using software designed for that objective. Results: It was find that the animals feeding in the same schedule of the experiments, presented higher exploratory activity associated to the enclosed arms and to the center of the EPM. The time spent on this places, would be the variables with the best sensitivity and specificity to recognize these effects. It does not discard the effect on the permanence time in the open arms. Conclusions and recommendations: The feeding schedule, influence significantly the rat behavior in the EPM, for that reason, it is recommended to consider this aspect in the experiments for anxiety studies. Salud UIS 2008; 40: 83-91