Substituted phenylactic acid iodopropargyl ester compounds of the general formula: ##STR1## in which R may represent hydrogen, fluorine, chlorine, bromine, iodine, methoxy, 1-imidazolyl or 1,2,4-triazolyl, X represents one or more of the same or different substituents selected from fluorine, chlorine, bromine, iodine, cyano, nitro, carboxyl, an alkyl having from 1 to 12 carbon atoms, an alkoxy having from 1 to 12 carbon atoms, a cycloalkyl having from 3 to 6 carbon atoms, formyl, acetyl, propionyl, benzoyl, phenylsulfonyl, phenyl, phenoxy, and substituted phenyl and phenoxy groups having from 1 to 3 substituents selected from fluorine, chlorine, bromine, nitro, methyl or methoxy, and n is an integer from 1 to 5 and may be zero provided that R does not represent hydrogen. The invention also relates to a process of making the compounds, which are effective ingredients of biocidal agents.