We have studied the effect of pressure on the superconducting transition temperature (Tc) of thorium doped La1-xThx FeAsO (x = 0.2) superconductor under hydrostatic pressures up to 1.6 GPa by resistivity and magnetization experiments. Application of pressure increases the Tc to 31 K with a positive pressure coefficient of ∼1 K/GPa. Low temperature X-ray diffraction studies performed at 7.8 K at high pressures show no pressure induced structural changes and the tetragonal P4/nmm structure is found to persist up to 31 GPa. (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) In this Letter, the effect of pressure on the superconducting transition temperature (Tc) of the thorium doped La1-xThxFeAsO (x = 0.2) superconductor is studied under hydrostatic pressures up to 1.6 GPa by resistivity and magnetization experiments. Application of pressure increases the Tc to 31 K with a positive pressure coefficient of ∼1 K/GPa. X-ray diffraction studies performed at 7.8 K show no pressure-induced structural changes, the tetragonal P4/nmm structure is found to persist up to 31 GPa. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.