This study aimed to identify the types of interventions of a psychoanalytic therapist in the psychotherapy of a patient with Borderline Personality Disorder, during a period of treatment prior to psychiatric hospitalization. The Systematic Case Study procedure was adopted with a quantitative design. For the data analysis, twelve sessions of psychotherapy were transcribed and analyzed and the interventions of the therapist were classifi ed based on the Modifi ed Multidimensional Classifi cation of Psychotherapeutic Interventions (CMIP-M), which identifi es types of interventions in clinical material. Pairs of independent judges trained in the methodology of the instrument evaluated and classifi ed each of the interventions of the therapist at the descriptive level. The results were presented by means of descriptive statistics of frequency and percentage and indicated predominance of empathic (27.3%), closed exploratory (24.1%) and psychoanalytical examination (15.1%) interventions throughout the investigation process. The results showed similarities with previous studies, indicating the emphasis on closed exploratory interventions in the treatment of personality disorders. However, there were differences in relation to the previous investigations carried out with patients diagnosed with Borderline Personality Disorder, in which expressive interventions predominated.