Resumo. This study investigated the diet of the endemic rodent Thrichomys laurentius Thomas, 1904 in a preserved fragment of the Caatinga in the municipality of Upanema, Rio Grande do Norte, Brazil. The research was based on fecal content analysis obtained from four monthly samplings across different climatic seasons. Food items were classified and quantified using the index of alimentary importance. The results showed a predominance of plant material (97.03%), followed by animal fragments (1.25%) and mineral particles (1.72%). Spearman's correlation revealed a negative association between plant consumption and increased rainfall, while the intake of animal items increased during the rainy season. The presence of stone fragments appears to be related to accidental ingestion. The dietary composition of T. laurentius demonstrated seasonal flexibility and a preference for plant items, suggesting ecological adaptations to semiarid dynamics. These findings provide novel data on the species' feeding ecology and offer valuable support for conservation strategies.