The dynamics of the Cl + D-2 reaction has been studied experimentally at the collision energies 4.9 and 6.3 kcal mol(-1) by the crossed molecular beam technique. The experimental results have been compared with theoretical predictions based on quasi-classical trajectory (QCT) calculations on the new BW potential energy surface (PES), and a good general agreement has been obtained. The QCT results obtained on the BW PES have been compared with those obtained on the previous semiempirical G3 PES, and striking differences regarding the effect of reagent rotation j on the reactivity have been found.