After the success of the two previous meetings on Typing of Hyperlipoproteinemias, in Milan in 1971 and in Rome in 1972, an important part of each of which was devoted to the discussion of therapy, the Italian Society for the Study of Atherosclerosis, the Institute Superiore di Sanita, and the Fondazione Giovanni Lorenzini planned a special treatment of this important topic. This meeting was held in Rome in November 1973 at the Istituto Superiore di Sanita. On this occasion the most important subjects developed in recent years by the most qualified centers of experimental and clinical research were reported. A broad discussion took place regarding the role of diet in causing or worsening the biohumoral changes and the lesions peculiar to arteriosclerosis, while other distinguished authors reported on the role of diet in delaying or correcting the dyslipidemic state.