This dissertation aims to examine the guilt question within the specific aspect of the obsessional neurosis. For that, we make a journey through Freud s main essays related to obsessional neurosis and, also, the ones regarding the superego; since we begin from the Freudian s hypothesis that the guilt feeling is a result of the tension between the superego and the ego. The particularly cruel tone that the superego assumes in the obsessional neurosis is examined. The defense mechanisms and the formation of the obsessive symptoms are also discussed. Ultimately, we make some considerations regarding Freud s clinical case known as The Rat Man, where we can find precious illustrations of the main mechanisms and characteristics that act in the obsessional neurosis.