In this contribution high-level ab-initio calculations of the chemical shifts of methanol including zero-point vibrational and temperature corrections are presented. For the first time, secondary isotope effects have been calculated via second order vibrational perturbation theory. In comparison with recent experimental gas-phase data and in contrast to other quantum-chemical methods the results are consistent and in very good agreement with the experimental C-13, O-17 and H-1 chemical shifts reported by Makulski [ W. Makulski, J. Mol. Struct. 872 ( 2008) 81]. Secondary isotope effects can be calculated with remarkable accuracy of a few hundredths of a ppm in comparison to experiment. (c) 2008 Elsevier B. V. All rights reserved.