Five of the atoms of the six-membered cyclo-hexene ring of the title compound, C(17)H(20)O(2), are essentially coplanar (r.m.s. deviation = 0.006 Å), with the sixth (the dimethyl-methyl C atom) deviating from the mean plane of the five atoms by 0.610 (2) Å. This plane is nearly perpendicular to the cinnamyl portion, the two planes being aligned at 85.1 (1)°. Two mol-ecules are linked by an O-H⋯O hydrogen bond about a center of inversion. The cyclo-hexene ring is disordered over two directly overlapping positions. As a result, the hy-droxy group and the keto O atom cannot be distinguished from one another.