Alzheimer's disease (AD) is the most common age-related neurodegenerative disease and an urgent public health problem in many areas of the world. We present the results of the activity of an ad hoc ward, called "Unità di Valutazione Alzheimer " (UVA) (Unit of Evaluation for Alzheimer), along the first two years of the "CRONOS" project (CP). We evaluated the efficacy and safety of acetylcholinesterase inhibitor (AChE-I) agents in the treatment of mild to moderate AD and the population served by the UVA. Three hundred fifty-four patients referred to our ward for cognitive deficits. According to the CP criteria, 66 patients (42 women and 24 men, mean age 74.1 +/- 5.8 years) were enrolled in the study. Evaluation was carried out at baseline and after 3, 9, 15, and 21 months. Our results showed a positive impact of these drugs on patients with mild to moderate AD during the first nine months of treatment. After this period, we observed a progressive lowering of the mini mental state examination (MMSE) scores, with a global impairment of 0.9-1 .0 points per year. The adverse events were generally not troublesome. Our data strongly support the usefulness of UVA in the AD case ascertainment during the early phase of the disease.Moreover, the CP provided a general better knowledge about this important and devastating disease.