The author reviews the current epidemiological concepts in Latin America, assesses the general mental health levels and sets forth some basic proposals aiming at the allocation and use of scarce resources, incorporating as an important one the community itself. The classic models for Mental Health Programs, defined through their basic infrastructures are analyzed: a) The Institution-Pscychiatric Hospital, aimed mainly at tertiary prevention, custody, and biologic therapy, and having high costs with reduced benefits; b) The Mental Health Unit, aimed mainly at secondary prevention, providing several services, and having high costs with good benefits; and c) The Comprehensive Program, aiming mainly at primary prevention, providing several specialized services together with the use of the resources of the community itself, and having low costs with high benefits. An overview of Mental Health indicators shows the following rates of prevalence: a) neurosis, 15%; b) alcoholism, 5%; c) epilepsy, 2%; d) psychosis, 1%; e) dementia, 1%; f) mental retardation, 1%. The total prevalence rate for the six basic psychopathological entities is 25%, in the population of more than 15 years of age. The minimal requirement of psychiatrists for that degree of prevalence is about 80/one million inhabitants, that is, an increase fourfold to fivefold of the present number. To attain this goal, at least 50 years are required, during which mental health services are likely to maintain their present deficits, unless a new conception of mental health services is used. The author proposes the generalized use of Comprehensive Programs, as the only possibility of providing within periods reasonably short an adequate service. The importance of incorporating the mental health resources of the community is stressed. The experiences made in Chile during three different governments, having different political and ideological basis, are briefed, showing the evidence of a number of advantages to be gained with the proposed system, in a relatively short timespan--less than 10 years.