A group of 80 elderly subjects affected with recent onset (less than 6 mth) slight to moderate mental deterioration was observed before and after oral drug treatment for a period of 28 wk. The study consisted of four randomized groups of subjects homogeneous for age, sex and life habits. The first group received a placebo, the second group received piracetam (1600 mg 3 times a day), the third group received pentoxifylline (400 mg 3 times a day), and the fourth group received a combination of piracetam and pentoxifylline. At the beginning and end of each phase of the study, neuropsychological and haemorheological parameters were evaluated in all subjects. The results show that the most evident improvement in psycho-intellectual performance, associated with an increase of whole blood filtration values, was obtained in the group treated with the two-drug combination.