This invention relates to a process for separating one or more phosphorus acidic compounds from a hydroformylation reaction product fluid containing said one or more phosphorus acidic compounds, a metal-organophosphite ligand complex catalyst and optionally free organophosphite ligand which process comprises (a) treating said hydroformylation reaction product fluid with water sufficient to remove at least some amount of said one or more phosphorus acidic compounds from said hydroformylation reaction product fluid and (b) treating the water which contains phosphorus acidic compounds removed from said hydroformylation reaction product fluid with an ion exchange resin sufficient to remove at least some amount of said one or more phosphorus acidic compounds from said water.