Starting from Comte's doctrine on brain physiology, the author advances the views that cerebellar cortex should be involved in the pathogenesis of cancer. According to that theory, the cortex of the vermis provides for the nutrition instinct, while neocerebellar cortex is responsible for the sexual drives. Hypothalamic nuclei are to be regarded as a relay in this system. Since cancer is recognized, in the last instance, as a disorganization of cellular growth, the author anticipated to find out cerebellar disturbances, clinical as well as histological, in cancerous patients; and this especially in cancer of the sexual organs at large. A thorough search into the neuropathological literature has steadily supported this starting viewpoint. Most authors who have reported on neuropathological findings associated with cancer or reviewed the corresponding literature emphasized consistently a specifical "Purkinje's atrophy", subacute and diffuse in type. Even though in many of such papers it is termed a secondary process, with the carcinoma as the causal factor, the correlation is by no means excluded because many authors agree that clinical symptoms of cerebellar failure are present even long before the cancer symptoms may be detected. The present writer calls attention to the mental symptoms pointing out to troubles of selfpreservation (nutritional) and/or sexual drives in the beginning of the clinical features, a fact which have not been stressed enough by the researchers. Chief aims of this preliminary report are to suggest: (a) that researches be directed towards finding out whether cerebellar disorganization - hence its clinical disturbances - are primarily responsible for cancer growth; (b) that clinical examination endeavor to detect fine neurological symptoms of cerebellar regulation; (c) that libido and erotic disturbances of behavior be investigated in the clinical history of cancer patients.