This paper presents preliminary results on the efficacy of acetyl-cholinesterase inhibitors (ChE-I) administered in a population of patients with mild-to-moderate Alzheimer's disease (AD), recruited in the context of an Italian Department of Health supported project (Progetto Cronos). The patients were followed up for a maximum of 21 months. Around 45% of the subjects responded well to the treatment (i.e., stable or improved Mini Mental State) at the end of the 9th month. Thereafter, a global cognitive and functional decline was reported, more marked in basic daily activities. No factors (age, sex, disease duration, family history for AD, cognitive impairment at baseline) emerged as predictors of outcome.