The vaporization enthalpies at T/K = 298.15 and vapor pressures from T/K = (298.15 to T-nb (normal boiling temperature)) of muscalure (Z-9-tricosene) and empenthrin [(E)-(RS)-1-ethynyl-2-methylpent-2-enyl (1RS)-cis-trans-2,2-dimethy1-3-(2-methylprop-1-enyl)-cyclopropane-carboxylate], have been evaluated by correlation gas chromatography. Commercial samples of muscalure also contain a small amount of E-9-tricosene. Vaporization enthalpies of [(114.4 +/- 1.0) and (114.5 +/- 1.0)] kJ.mol(-1) and vapor pressures, p/Pa = [(1.2 +/- 0.1) and (1.1 +/- 0.1)].10(-4), both at T/K = 298.15 have been evaluated for Z and E-9-tricosene, respectively. Empenthrin is also a mixture of possibly four diasteriomers. Two of the diasteriomers, empenthrin 1 and 2, are separated by the chromatography and are characterized by the order of their elusion off the column. Vaporization enthalpies of [(87.2 +/- 4.8) and (87.0 +/- 4.8)] kJ.mol(-1) and vapor pressures, p/Pa = [(594 +/- 380) and (601 +/- 383)].10(-4), also at T/K = 298.15 have been evaluated for the two diasteriomers, empenthrin 1 and 2, respectively. Vapor pressure equations generated by correlation for muscalure predict a boiling temperature at p/Pa = 133 of T-b/K = 449 (lit. 453) and for empenthrin 1 and 2 at p/Pa = 101325 of T-nb/K = 567.9 and 569.2 (lit. 568.7). The vapor pressure values for empenthrin at T/K = 298.15 serve as a test case for comparing the accuracy of vapor pressure measurements using other GC retention time methods on environmentally sensitive materials.