This is a clinical case report on young female patient aged 30 whom the author has followed with a mixed treatment of psychotherapy and chemotherapy for one and a half year. This patient has a "borderline" symptomatology. The approach through counter-transfer is preponderant. The importance and use of this analysis are emphasized, first to allow a dynamic research of adequate therapeutic attitudes, then to furnish basic knowledge for understanding the type of material and anxiety brought up by this patient. A more comprehensive reflexion is made concerning the situations leading to the use of a first, then second psychotherapeutic drug, in parallel to the psychotherapeutic approach, and to the problems resulting in the therapeutic relationship throughout the transfer and counter-transfer.