<p>This study investigates the effects of hysteresis on shear-induced matric suction and the undrained shear behavior of low-plasticity clayey sand and non-plastic silt through a series of unsaturated triaxial tests conducted under constant water content conditions. Hysteresis was examined by comparing specimens subjected solely to a drying path with those undergoing both drying and wetting paths. Results indicate that, at the same initial matric suction, specimens following the drying path exhibit lower shear strength compared to those exposed to a drying–wetting path. This difference is attributed to the influence of matric suction history, which leads to decreasing matric suction during shearing for the drying path, and increasing suction during shearing for the drying–wetting path. Empirical relationships between initial and at-failure matric suction were established using both experimental data and supplemental findings from the literature. A consistent correlation between shear strength and matric suction at failure was observed for each soil type, linear for clayey sand and nonlinear for silt, regardless of hysteresis effects. These findings highlight the limitations of using initial matric suction alone to predict undrained shear strength and contribute to an understanding of the undrained behavior of unsaturated soils.</p>