Aim: To establish a helpful relationship between the nurse and the first-birth puerperal adolescents based in Peplau´s interpersonal relationship theory. The North American Nursing Diagnosis Association (NANDA) diagnostic taxonomy is applied to foresee the patient´s answers regarding her state of health. Material and methods: The study was followed during November and December 2004 with an adolescent puerperal and the scenario was a common ward in a Public Maternity Clinic and the new mother´s home. One visit was at the hospital and three were domiciliary. Results and conclusions: During those visits the Peplau´s interpersonal process was followed with its observations and interview techniques. This study helps to know the purposes of the theory which systematized and guided the assistance to the adolescent mother. Besides it stresses the benefits of the theoretical models in nursing care.