Basic investigation in industrial laboratories are mainly addressed to widespread diseases. It follows that: 1) basic research is addressed chiefly to the well known and largely diffuse diseases; 2) rare diseases are not usually studied and therefore little chance is given to their physiopathological or therapeutic knowledge. Hence the name of orphan diseases. The aim of this study is to contribute to the stimulation of innovative and applied basic research of orphan diseases and therefore to gradually confine the number of incurable rare diseases. Our proposal upsets the studies undertaken in some foreign countries and Italy on the orphan drugs (e.g. Orphan Drug Act, issued in the USA in 1982) since we suggest starting from a study on disease more than studies on drug. The planning of studies of disease may be undertaken on various points of view (prevalence, clinical features, prognosis, social cost, etc.), while this may be very hard for the drug. Therefore we suggest starting from a study plane, classification and estimation of rare diseases, shared for apparatus. These studies may be undertaken on a vigorous rationale (more than studies on orphan drugs) and therefore they may bring about to the definition of a national (government) planning for addressing consistent financial resources to the study of pathophysiology and therapy (or prevention) of the major orphan diseases. Adequate studies within the European Community may be planned in the near future, since most rare diseases are presumed to have a common distribution within the Community.