We report the first observation of the photorefractive effect in cadmium sulfide at low optical power. The maximum gain coefficient measured with no applied field at 633 nm is 0.3 cm−1. The response time scales sublinearly with intensity and is independent of grating spacing. At a maximum intensity of 80 mW/cm2, a response time of 0.9 ms is obtained. The photorefractive sensitivity is the largest among photorefractive material operating in the visible range.