Using a variable path interferometer, ultrasonic velocity dispersion in 3-methylcyclohexanone was studied in the temperature range 323.15 K to 363.15 K and in the frequency range 0.5 MHz to 5.0 MHz. The relaxation parameters were evaluated from the experimental data. These values were utilised to evaluate the energy parameters; the differences in the enthalpy (ΔH0), the free energy (ΔG0), and the entropy (ΔS0) are 2.79 kcal/mol, 0.88 kcal/mol, and 5.9 cal/mol K, respectively. The enthalpy (ΔHr) for the backward reaction was 7.63 kcal/mol.