Ethnic foods are healthy products interesting for the new societies. Mesquite flour offers another option for making gluten-free recipes as part of a diet for people with celiac disease. The physicochemical properties of mesquite flours (Prosopis laevigata) were characterized. The mesquite pods were dried at 60°C, 15% RH and 2 m/s airflow; then a grinding and sieving process were applied. The nutritional composition and the sorption isotherms were obtained at 30, 35, 40 and 45°C for water activities of 0.07-0.9. The particle-size distribution, morphology and thermal stability of the flours were determined by different methods. Keywords: Mesquite Flours; drying; isotherms; chemical properties; morphology