The effects of surface modification of commercial reverse osmosis (RO) polyamide membranes were studied as a function of flux/rejection and surface properties. Selected ultra-low pressure RO membranes were modified by in situ crosslinking of either hyperbranched polymers (HBPs) or polyamidoamine (PAMAM) dendrimers and polyethylene glycols (PEG). As expected, surface and chemical modification of membranes significantly reduced their contact angles as measured by dynamic as well as static contact angle measurement techniques. Lower contact angles indicate more hydrophilic membranes with potential for increased resistance to fouling by hydrophobic foulants, such as biofoulants and organic materials.