Hall effect of photoelectrons in cadmium sulfide has been studied in the temperature range from room temperature down to 1.8°K using the Redfield method operated by pulse circuits. The low field Hall mobility is found never to decrease at low temperatures in contrast to the previous investigations. The highest observed mobility is 5× 10 4 cm 2 /volt sec at 1.8°K which is the same order of magnitude estimated from the cyclotron resonance measurements. Below 25°K, the mobility increases according to T -1/2 as the temperature is lowered. The general feature of the dependence of low field Hall mobility on temperature is described by the combination of scatterings by optical vibrations of lattice and piezoelectric effects. Anisotropy in mobility is observed only in the temperature region where the piezoelectric scattering dominates. The ratio of µ a to µ c is found to be 1.5±0.1. The results of high magnetic field effect on the Hall effect are analysed by the theory of Burnham, Brown and Knox with the observed low field mobilities.