We investigated picture naming in Spanish-speaking patients with probable Alzheimer's disease using coloured line drawings of actions and objects matched on several key psycholinguistic variables. The patients were less accurate than healthy controls but we found no significant evidence for an effect of grammatical class. Generalized linear mixed-effects analyses indicated that patient naming accuracy was affected by lexical frequency and age of acquisition, and by the name agreement of the pictures. These observations support the view that, while the effect of grammatical class is not an important influence, accurate picture naming in dementia is determined by the impact of lesions on a lexico-semantic mapping structured by experience. (c) 2008 Elsevier Ltd. All rights reserved.