To provide a method for industrially advantageously producing zaltoprofen as an anti-inflammatory/analgesic agent.

The method comprises the following process: Zinc iodide, sodium cyanide or potassium cyanide, and trimethylsilyl chloride are added to a compound of formula(I) followed by mixing them together to carry out a reaction to form a compound of formula(II). Sodium cyanide or potassium cyanide, trimethylsilyl chloride, acetonitrile and water are added to the compound of formula(II) followed by mixing them together to carry out a reaction to form a compound of formula(III). Polyphosphoric acid is made to act on the compound of formula(III) to effect cyclization, followed by addition of water to form a compound of formula(IV), which is then hydrolyzed to obtain the objective compound(zaltoprofen) of formula(V). In the above formulas, R is a lower alkyl.