The effects of 10‐MeV electron irradiation on the photoconductivity of CdS single crystals were studied. Irradiation causes the appearance or increase of photoconductivity in the wavelength ranges from 0.8 to 3 &mgr; (the 1‐&mgr; band), from 0.55 to 0.8 &mgr;, and from 0.46 to 0.5 &mgr; (the exciton band). The 1‐&mgr; band is attributed to radiation‐produced defects located at levels from 0.4 to 1.6 eV below the bottom of the conduction band. The excitonic band results from dissociation of excitons at some kinds of radiation‐produced defects.