Pitzer et al. (1955) three-parameter (T\sbc, P\sbc,ω) corresponding states principle (CSP) correlations for saturated properties are extended to long-chain n-alkanes and to other classes of compounds by use of n-alkane reference fluid properties. New vapor pressure measurements, a critical review of the n-alkane literature, and numerous correlational studies are described. Direct vapor pressure measurements of zone-refined n-alkanes (decane, dodecane, tetradecane, hexadecane, octadecane, nonadecane, eicosane, docosane, tetracosane, and octacosane) are reported in the 0.1 to 1400 kPa and 323 to 588\sp∘K pressure and temperature ranges. These results allow the evaluation of existent data and the subsequent development of accurate correlations for vapor pressures and heats of vaporization. Wagner equation fits, which are scaled using the T\sbc and P\sbc correlations of Twu (1984) for the longer n-alkanes, are given for representing vapor pressures of n-alkanes over the liquid-vapor coexistence range. The scarcity of low-pressure data in the vicinity of the triple point is addressed by use of two-real-fluid CSP techniques (Ambrose & Patel, 1984) to extrapolate data available at higher pressures. Observations of triple point corresponding states in the long-chain n-alkanes suggest an alternative approach for fitting vapor pressure equations at low-pressures. Extensions of Pitzer-type CSP correlations to long-chain n-alkanes (C\sb36+) are achieved in two ways. First, a second-order perturbation term in Pitzer's acentric factor expansion of In(P\sbr) is included. This approach is referred to as the PERT2 model. In a second method, parameters (P\sbc, ω) for a two-fluid CSP model based on methane and n-octane, C\sb1/C\sb8, are determined by regression of vapor pressures. The two models are compared with experimental data and literature correlations. Applications of the n-alkane-based correlations to other classes of compounds, such as model compounds derived from coals, are given. Extensions of Pitzer-type CSP correlations to associated fluids are briefly considered by applying two- and three-fluid CSP models.