In this paper we propose the preparation of a PtSn bimetallic catalyst through techniques derived from Surface Organometallic Chemistry on Metals (SOMC/M) using water as solvent. The system, PtSn0.2ac, was employed in the chemoselective liquid-phase hydrogenation of acetophenone, cinnamaldehyde and benzaldehyde. The results were compared with those obtained with a PtSn catalyst also prepared via SOMC/M, but using a conventional paraffinic solvent. The aqueous medium-prepared catalyst resulted to be as active in and selective to the desired product (unsaturated alcohols) as that obtained from n-heptane. This catalyst has the advantage of being prepared in a solvent compatible with the environment, without losing the superior characteristics of SOMC/M-based systems.Centro de Investigación y Desarrollo en Ciencias Aplicadas