Experimental solubilities are reported for pyrene dissolved in ternary 1-propanol + 1-butanol + heptane, 2-propanol + 1-butanol + heptane, 1-propanol + 2-butanol + heptane, and 2-propanol + 2-butanol + heptane solvent mixtures at 26°C and atmospheric pressure. Nineteen compositions were studied for each of the four solvent systems. Results of these measurements are used to test the predictive ability of the ternary solvent form of the combined NIMS/Redlich-Kister equation. Computations showed that the model predicted the observed solubility behavior to within an overall average absolute deviation of about 1.6%, which is comparable to the experimental uncertainty of (1.5%.