The solubility of rifapentine in acetic acid and n-octanol solvent mixtures was measured at temperatures ranging from (278.15 to 323.15) K. The mole fraction of n-octanol in the solvent mixtures (x(3)) range from 0.0 to 0.5993. For the seven group data studied, the experimental solubility data were well-correlated with the data, calculated by means of a semiempirical equation.