Transport properties of semiconducting rhenium silicide ReSi 1.75 were studied both experimentally and theoretically. For this high quality ReSi 1.75 single crystals were grown by the zone melting technique with radiation heating and their resistivity and Hall coefficient were investigated. The room temperature carrier concentration in undoped material is appreciably high, about 10 19 cm −3. The Hall mobility at room temperature is 30 cm 2/V·s, that is considerably lower than previously reported values for single crystals. P-type conductivity persists across the entire interval investigated. Calculation of the charge carrier mobility involved the carrier effective masses, which were obtained from the ab initio electronic band structure and classical scattering mechanisms. A reasonable explanation of the hole mobility behavior is proposed and a strong anisotropy in hole effective masses and mobilities is predicted.