A fluorene derivative of high purity is produced by reacting fluorenone with phenoxyethanol in the presence of a sulfuric acid-thiol catalyst system, dissolving the reaction mixture in a lower aliphatic alcohol and adding water to the resulting solution for precipitation of 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene [fluorene derivative]. A fluorene derivative of still higher purity is obtained by recrystallization from a lower aliphatic alcohol.In accordance with this invention, a fluorene derivative can be produced advantageously on a commercial scale without incurring any appreciable loss of fluorenone, in good yield, with high efficiency and in a reduced production time.