The interest in therapeutical applications of carbon monoxide to physiological targets has led us to explore CO releasing molecules (CORM’s), particularly those that decomposes upon a specific stimuli, i.e. light irradiation. Here, we prepared a photoactivated, air stable and water soluble ruthenium(II) complex, cis-[Ru(bpy)2(SO3)(CO)], which releases carbon monoxide upon light irradiation. Indeed, many CORMs face very limited water solubility calling for improving this drawback. Photolysis of this complex using UV light in aqueous solution leads to high quantum yield of a single CO release. The release of CO was confirmed by myoglobin assay, and a careful monitoring of this photo-reaction was performed using HPLC. Our results showed it might serves as a carbon monoxide releasing moiety, which can be induced photochemically. Despite the lack of pharmacological and toxicological studies, these results are quite encouraging and might eventually lead this compound to become a relevant pharmacological agent.