The current study employs the Pulse Thermal Analysis (PTA) method to investigate the adsorption of gaseous methanol onto various forms of aluminium trifluoride drawing special attention to the strongly adsorbing beta-AlF3 and the recently described high-surface (HS) AlF3. Simultaneously or subsequently occurring physisorption and chemisorption can be clearly distinguished and partly quantified. BET surface and NH3-TPD data will be discussed together with the surface coverage by methanol determined by TA. The extraordinary sorptive properties of HS-AlF3 are due to acidic sites at the remarkably large surface. The crystalline modifications eta-AlF3, theta-AlF3, and kappa-AlF3 are less-important as they poorly adsorb exhibiting thermogravimetric curves without clearly expressed mass changes. Their surface loading is comparably poor as found for the stable modification alpha-AlF3. (C) 2009 Elsevier B.V. All rights reserved.