New measurements of the thermal conductivity of n-docosane, n-tetracosane, 1,6-hexanediol, and 1,8-octanediol, in the solid and liquid phase, are presented. The technique employed is the transient hot-wire technique, based on a full theoretical model. The technique is absolute and is characterized by an uncertainty of 1%. At the 95% confidence level, the standard deviations of the thermal conductivity measurements of n-docosane, are 0.40% for the solid phase (267 K to 308 K), and 0.60% for the liquid phase (330 K to 360 K); of n-tetracosane, 0.60% for the solid phase (265 K to 306 K), and 0.30% for the liquid phase (339 K to 363 K); of 1,6-hexanediol, 0.70% for the solid phase (263 K to 296 K), and 0.40% for the liquid phase (327 K to 351 K); and of 1,8-octanediol 1.1% for the solid phase (265 K to 312 K), and 0.50% for the liquid phase (344 K to 356 K), respectively.