The collision-induced intramolecular energy flow and C-H bond dissociation in toluene have been studied using classical dynamics procedures. The molecule initially contains high amounts of vibrational excitation in the methyl C-H stretch and the nearby benzene ring C-H stretch and it is in interaction with Ar. The two excited C-H stretches are coupled to each other through two C-C stretching, two H-C-C bending and one C-C-C bending modes, all of which are initially in the ground state. At 300 K, the energy lost by the excited molecule upon collision is not large and it increases slowly with increasing total vibrational energy content between 10 000 and 40 000 cm(-1). Above the energy content of 40 000 cm(-1), energy loss increases rapidly. Near 65 000 cm(-1) energy loss takes a maximum value of about 1000 cm(-1). The temperature dependence of energy loss is weak between 200 and 400 K. When the energy content is sufficiently high, either or both C-H bonds can dissociate, producing free radicals, C6H5CH2, C6H4CH3, or C6H4CH2. The ring C-H dissociation occurs almost entirely in a direct-mode mechanism on a subpicosecond time scale. Nearly half of methyl group C-H dissociation events occur on a subpicosecond time scale and the rest through a complex-mode collision in which bond dissociation occurs several picoseconds after the initial impact. In the complex-mode collision, Ar binds to the radical forming a weakly bound benzyl...Ar complex. In both dissociative and nondissociative events, intramolecular energy flow is efficient, taking place upon the initial impact on a subpicosecond time scale.