Two maize-grit samples obtained from a dent and a flint type of maize, having NIR hardness values of 300 and 546, respectively, were extruded at two different temperatures, 150 and 180°C and at a moisture content of 15 g moisture/100 g sample using a Brabender 10DN extruder. Expansion and cooking degrees were determined. Mechanical resistance of samples at different water activities was evaluated taking the area under the compression force–deformation curve. The triangle test was used to determine the differences in texture among samples. The results showed that expansion and cooking degrees were higher for flint maize samples. Mechanical test indicated that area values of dent maize samples were significantly higher than the ones corresponding to flint maize, in all cases. Also, the effect of temperature was significant, particularly for samples at a w between 0.23 and 0.43. Sensory evaluations for texture were in agreement with those of the mechanical ones. The results of this research allow us to conclude that flint maize, being harder than dent maize, gives greater expansion values with higher degree of cooking and lower mechanical resistance, which means a better texture, thus supporting the preference of the snack industry for flinty maize grits. It is worthy to note that the difference in hardness shown by the maizes under study is normally found among commercial cultivars.