Collision-induced dissociation, He+H-2--> He+H+H, is studied by using a semiclassical method in which one degree of freedom (i.e., intermolecular radial motion) is described by classical mechanics and the others by quantum mechanics. In the present semiclassical treatment, the quantum motions, i.e., vibration, dissociation, molecular rotation, and intermolecular angular motion, are solved accurately without introducing any decoupled approximations. The energy dependence of the dissociation cross section and the translational and angular momentum distributions of dissociative fragments are calculated at the total energies E less than or equal to 10 eV. Also carried out is the semiclassical calculation using a centrifugal sudden approximation, and the reliability of this approximation for the dissociation process is examined. (C) 2000 American Institute of Physics. [S0021-9606(00)01110-7].