This work was motivated by previous pheromone trap tests for Conogrthes sp. and C. punctiferalis in which small numbers of Pleuroptia chloropahanta males were unexpectedly trapped. Formulations of (E)-10-hexadecenal (E10-16: Ald), (Z)-10-hexadecenal (Z10-16: Ald), n-hexadecanal (n-16: Ald) or (E)-10-hexadecenol (E10-16: OH) alone or in various combinations were tested as attractants for male moths of P. chloropahanta in different plantations. In chestnut and peach orchard field tests in 1994, E10-16: Ald alone was attractive to the males but binary mixtures of E10-16: Ald and 5 to 50% of Z10-16: Ald were not attractive. Trap catches by a binary mixture of E10-16: Ald and E10-16: OH in 1995 was very low and not different from that of a 4-component mixture for C. punctiferalis. In field tests of two Japanese white pine plantations of in 2001, 36 P. chloropahanta males were caught by traps baited with E10-16: Ald alone. Conclusive results, that is, exclusive attraction by E10-16: Ald were also obtained by field trap tests in plantations of Paulownia tomenyosa and Syrax abassia, host plants of this species. These results strongly suggest (E)-10-hexadecenal is effective as a sex attractant for monitoring P. chloropahanta and this compound may be one of the sex pheromone components of this species.