The reaction of SiHCl 3 with atomic O( 3 P) has been studied theoretically for the first time. In C s symmetry, two nearly degenerate saddle points of 3 A ' ' and 3 A ' symmetries have been located. The kinetics nature has been deduced using canonical variational transition state theory (CVT) with small-curvature tunneling (SCT) correction over a wide temperature range of 200-3000 K. The calculated CVT/SCT rate constants show reasonable agreement with the available experimental values, with a more pronounced curvature in the Arrhenius plot than in the experimental data.