A purified p-phenylphenol is obtained by reduction of the m-phenylphenol percentage from crude or technical grade p-phenylphenol by contacting the mixture with a molar quantity of caustic less than heretofore employed, whereby the m-phenylphenol preferentially reacts to form sodium m-phenylphenate while the p-phenylphenol ends up as a solid in substantially pure form. The amount of the caustic is from about 0.5 to about 10 moles of caustic per mole of m-phenylphenol present. Resin grade p-phenylphenol, i.e., containing less than 2% m-phenylphenol can be obtained from a starting material containing up to 30% m-phenylphenol.