Eleven outpatients with Alzheimer disease of moderate severity completed a double-blind placebo-controlled crossover trial of lecithin. Each patient received 10 gm three times daily of a placebo for 3 months. Plasma choline levels rose threefold and remained at that level throughout the lecithin administration period. A significant difference between mean baseline scores and treatment scores was found on tests of new learning ability, indicating a practice effect in there tests. However, there were no differences between mean placebo and lecithin scores on any of the psychological test measures.