Isotherms are presented for adsorption of H2O(g) on LiAlO2 at 573, 623, and 873K together with isotherms reported earlier for 673 and 773K. From these data, isobars and isosteres were derived. Analysis of the data suggests that two adsorption processes are involved: physisorption at 573K and below, and chemisorption at 873K and above. Both processes function in the intervening temperature range. Corrections were applied to the raw adsorption data, which were obtained by the breakthrough technique, for postbreakthrough uptake of H2O(g). Adsorption on non-BET surfaces is believed to be involved in these corrections for the lower temperature isotherms.