The cyclopentadienyl molybdenum carbonyl complexes [(η5-C5H4R)Mo(CO)2(η3-C3H5)] and [(η5-C5H5)Mo(CO)3(CH2R)] (R = H, COOH) have been shown to promote acid-catalysed reactions in liquid phase, under moderate conditions. The catalytic alcoholysis of styrene oxide with ethanol at 35 °C gave 2-ethoxy-2-phenylethanol in 100% yield within 30 min for the dicarbonyl complexes and 3–6 h for the tricarbonyl complexes. Steady catalytic performances were observed in consecutive runs with the same catalytic solution, suggesting fairly good catalytic stability. In the second acid-catalysed reaction studied, the isomerization of α-pinene oxide at 55 °C gave campholenic aldehyde and trans-carveol in a total yield of up to 86% at 100% conversion. Chemoselectivity is shown to be solvent dependent.