A process for producing optically active 4-hydroxy-2-cyclopentenone [1] which comprises reacting 4-hydroxy-2-cyclopentenone represented by the formula: ##STR1## with an optically active propargyl alcohol derivative represented by the general formula: ##STR2## wherein R and R.sup.1 each independently represent a halogenated phenyl group, an alkylphenyl group, or an alkyl group which may be substituted with one or more halogen atom(s), and * indicates an asymmetric carbon atom, to form an optically active complex [3] consisting essentially of optically active 4-hydroxy-2-cyclopentenone represented by the formula [1] ##STR3## wherein * indicates an asymmetric carbon atom, and the optically active propargyl alcohol derivative [2], and then decomposing the optically active complex [3].