Parallel with the development of hypotheses regarding cholinergic involvement in geriatric memory dysfunction, the first attempts to treat patients with Alzheimer's disease (AD) involved the cholinergic-precursor loading approach. Despite encouraging early results, well-controlled clinical trials did not confirm a clinical utility of cholinergic precursors such as choline and lecithin (phosphatidylcholine) in AD. This study assessed the efficacy and tolerability of the cholinergic precursor choline alfoscerate (CA) in the treatment of cognitive impairment due to mild to moderate AD. In this multicenter, double-blind, randomized, placebo-controlled trial, patients affected by mild to moderate dementia of the Alzheimer type were treated with CA (400-mg capsules) or placebo capsules, 3 times daily, for 180 days. Efficacy outcome measures that were assessed at the beginning of the investigation and after 90 and 180 days of treatment included scores of the Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog), the Mini-Mental State Examination (MMSE), the Global Deterioration Scale (GDS), the Alzheimer's Disease Assessment Scale-Behavioral Subscale (ADAS-Behav), all items of the Alzheimer's Disease Assessment Scale (ADAS-Total), and the Clinical Global Impression (CGI) scale. The Global Improvement Scale (GIS) score was assessed after 90 and 180 days of treatment. A total of 261 patients (132 in the CA group, 129 in the placebo group) were enrolled in the study. The mean (SD) age in the CA group was 72.2(7.5) years (range, 60-80 years), and in the placebo group it was 71.7 (7.4) years(range, 60-80 years). The CA group comprised 105 women and 27 men; the placebo group, 94 women and 35 men. The mean decrease in ADAS-Cog score in patients treated with CA was 2.42 points after 90 days of treatment and 3.20 points at the end of the study (day 180) (P < 0.001 vs baseline for both), whereas in patients receiving placebo the mean increase in ADAS-Cog score was 0.36 point <1 after 90 days of treatment and 2.90 points after 180 days of treatment(P < 0.001 vs baseline). In the CA group, all other assessed parameters (MMSE,GDS, ADAS-Behav, ADAS-Total, and CGI) consistently improved after 90 and 180 days versus baseline, whereas in the placebo group they remained unchanged or worsened. Statistically significant differences were observed between treatments after 90 and 180 days in ADAS-Cog, MMSE, GDS, ADAS-Total, and CGI scores and after 180 days of treatment in ADAS-Behav and GIS scores. The results of this study suggest the clinical usefulness and tolerability of CA in the treatment of the cognitive symptoms of dementia disorders of the Alzheimer type.