Within the context of the European Network study of Borderline Personality Disorder Adolescents, using projective testing methods (Rorschach and T.A.T.) and in the perspective of psychoanalytical interpretation, we have studied the psychic functioning of 22 borderline adolescents, of which 11 suffer from eating disorders. Within these 2 subgroups Borderline Eating Disorders and Borderline Non Eating Disorders few apparent differences have arisen. This finding has initiated our interest in anorexic and bulimic patients. The psychic functioning of these patients showed defensive articulation; problematiques and conflicts underlying the symptoms; and specific transferential movements. In spite of the usual stereotypical behaviour in anorexis and boulimic patients, the projective testing illustrates two major types of functioning. One of which is retrained associative output and defensive inhibition; and the other, massiveness of the projection and production effervescence. Contrasting, on one side emptiness and weak fantasmatic capacity and the other an excess of fantasmatic productivity. These considerations have an impact on the therapeutic modalities. The contribution of the projective methodology and the refinement in the diagnosis constitutes a considerable aid.