PURPOSE: To obtain an aromatic hydroxyl compound in high selectivity, by hydrolyzing 4,4'-diiododiphenyl, etc., in the presence of a copper compound, etc., and an alkali metal hydroxide under mild condition using dimethylsulfoxide as a solvent.

CONSTITUTION: The objective compound is produced by hydrolyzing a 4,4'- diiododiphenyl-type aromatic iodide of formula I (X is -O-, -, -CH2-, -SO4- or group of formula II) in dimethylsulfoxide solvent in the presence of a copper compound such as CuI, Cu2O, etc., or an iron compound such as FeO, an alkali metal hydroxide such as KOH and optionally water in solubilized state preferably at 80W250°C, especially 100W180°C. The amount of dimethyl-sulfoxide is preferably 2W40pts. per 1pt. of the compound of formula I and the molar ratios of the copper compound and the alkali metal hydroxide to the compound of formula I are preferably 0.05W10 and 1W20, respectively.