The non-reductive ring-opening/dehydrocoupling copolymerisation of epsilon-caprolactone with various primary hydrosilanes (RSiH3: phenylsilane, p-tolylsilane, benzylsilane, p-methylbenzylsilane and phenethylsilane) and secondary hydrosilanes (RR'SiH2: phenylmethylsilane and diphenylsilane) using Cp2MCl2/Red-Al (M = Ti, Zr, Hf) combination catalysts produced random copolymers, poly(caprolactone-co-silane)s, in good yield. For all the primary hydrosilanes the polymerisation yield and molecular weight decreased in the order Ti > Zr > Hf whereas the thermogravimetric analysis (TGA) residue yield increased in the order Ti < Zr < HE The molecular weights with secondary hydrosilanes were higher than those with primary hydrosilanes, while a reverse trend was observed for TGA residue yield. A plausible mechanism for the formation of the random copolymers is provided. (c) 2006 Society of Chemical Industry.