A flow-mixing calorimeter has been used to measure the excess molar enthalpy H-m(E)(p degrees) of (nitrogen + dioxane)(g) at standard atmospheric pressure (p degrees) over the temperature range (373.2 to 423.2) K. The measurements were analysed using pair potential parameters for nitrogen, assuming suitable combining rules for the calculation of cross-terms, and finding Kihara potential parameters for dioxane which fitted the excess enthalpy measurements. These parameters are epsilon/k = 920 K, sigma = 0.506 nm, and a = 0.095 nm. Second virial coefficients calculated from these parameters are about 50 cm(3).mol(-1) more negative than values calculated from the corresponding states correlation of Tsonopoulos. There are no experimental values with which to make comparison.