The feeding habits of a population of Liolaemus laurenti in northwest Argentina were studied in an annual period of activity. The objectives of the study were to determine the composition of the diet of the species, the trophic diversity and variations between sexes and among dry and wet seasons. From the analysis of 42 stomach contents, it was determined that ants constitute the main prey category of the diet, they comprise 93.15% of all present prey; it was also the most frequent category (100% of stomach contents). Lizard population also feeds on other insects and chelates. The trophic diversity was higher in females and in both in males and females increases during the wet season. Seasonal differences could be attributed to the fact that in arid ecosystems rainfall strongly affects productivity primary. Therefore the supply of resources for arthropods in general and therefore, for their predators.