Vapor pressures of 1-aminonaphthalene, 1,8-diaminonaphthalene, 1,5-diaminonaphthalene, N,N-dimethyl-1-aminonaphthalene, 1,8-N,N,N',N'-tetramethyldiaminonaphthalene, and 1,5-N,N,N',N'-tetramethyldiaminonaphthalene have been determined by the transpiration method. The molar enthalpies of sublimation and the molar enthalpies of vaporization have been determined from the temperature dependence of the vapor pressure. Experimental vaporization and sublimation enthalpies were checked for internal consistency with help of available data on fusion enthalpies.