Abstract: Phenols, and related aromatic compounds, phenolic ethers, can be hydroxylated selectively using hydrogen peroxide in the presence of an amorphous or crystalline tin or cerium phosphate catalyst in a solvent containing an aliphatic carboxylic acid. The process is particularly suitable for phenol itself, and advantageously employs a catalyst obtained by heating an hydrated amorphous or crystalline tin or cerium phosphate for example at about 100.degree. C. A convenient hydroxylation temperature is in the range of 50.degree. to 90.degree. C., and a convenient solvent is acetic acid.