We present a direct ab initio dynamics study of thermal rate constants of the abstraction reaction of BCl3 + H --> BCl2 + HCl. The geometries of all the stationary points are optimized at a variety of DFT and QCISD methods with both 6-31+G(d,p) and 6-311+G(d,p) basis sets. The energies are refined at the MC-QCISD, G3, G3MP2 and QCISD(T)/6-311 +G(2df,2pd) level of theory. The rate constants are evaluated using the conventional transition-state theory, canonical variational transition-state theory and canonical variational transition-state theory with small curvature tunneling correction. (C) 2003 Elsevier Science B.V. All rights reserved.