The vapor-phase Raman spectra of an atmosphere of cyclohexane vapor heated to 90 and 110 degrees C collected over a large period of time and utilizing a high laser power of 4 W show hot band series starting at 380.8 cm(-1) and corresponding to the v(6)(A(1g)) ring-inversion-vibration. Fitting this data with a one-dimensional potential energy function allows the barrier to planarity of 8600 cm(-1) (24.6 kcal/mol) to be calculated. Ab initio calculations (MP2/cc-pVTZ) predict a value of 10 377 cm(-1) (29.7 kcal/mol), while DFT (B3LYP/cc-pVTZ) calculations predict 8804 cm(-1) (25.2 kcal/mol).