Psychology, psychoanalysis, and psychiatry have shown interest in many personalities of the past, but no one in Niccolò Machiavelli (1469-1527), notwithstanding the richness of his anthropology. This paper tries to fill this gap. It approaches Machiavelli’s works in strict connection with his correspondence and with the development of his relationships with friends and women. In so doing, it delineates an image of Machiavelli which is somewhat different from the current one. This image can suggest a critical reflection about some crucial concepts of the above mentioned disciplines of psychology, psychoanalysis, and psychiatry.