4 We theoretically studied the Rayleigh-Benard convection in homeotropic nematic liquid crystal cells due to the absorption of a Gaussian light beam, which penetrates the cell normally from above. It was shown that a convection of hydrodynamic motion in nematic liquid crystals can be induced as a result of absorption Gaussian beam and consequently, can lead to hydrodynamic motion and significant director reorientation in liquid crystal cells. The results can be easily measured experimentally.