Zeolite titanium Beta is found to be an effective catalyst for the industrially relevant rearrangement of alpha-pinene oxide to campholenic aldehyde, giving selectivities of up to 89% in the liquid phase. In the gas phase, up to 94% selectivity is obtained at conversions above 95%, which exceeds the best values obtained with homogeneous Lewis acid catalysts. The selectivity obtained is profoundly influenced by the solvent or co-adsorbate applied.