The title compound, C(24)H(22)O(4)S, was prepared by reaction between (2E)-3-(6-meth-oxy-2-naphth-yl)-1-(2-thien-yl)prop-2-en-1-one and ethyl acetoacetate. In the crystal, the cyclo-hexenone ring shows a distorted half-chair conformation. The length of the double bond in the cyclohexenone ring [1.343 (4) Å] is normal.