Ethyl phenylphosphinate is an organophosphorous compound. It undergoes regioselective Markovnikov addition reaction with terminal alkynes in the presence of palladium-1,2-bis(diphenylphosphino)ethane complex (catalyst). Ethyl phenylphosphinate is the photodecomposition product of Inezin (S-benzyl O-ethyl phenylphosphonothiolate) on the ultraviolet irradiation. It can be prepared by the reaction of phosphinic acid with ethyl chloroformate in the presence of pyridine. Its ethylation using ethyl trimethylsilyl phenylphosphonite or the corresponding trimethylstannyl ester has been described. Its free-radical addition to ethylene has been reported to proceed with the retention of configuration.