Speed of sound for the binary mixtures hexane + 1-chlorohexane, hexane + 1-iodohexane, and 1-chlorohexane + 1-iodohexane has been measured as a function of composition and temperature along the saturation line between 293.15 K and 373.15 K. Nonlinear behavior is observed with temperature and concentration. The experimental results are correlated with polynomial equations of the second power.