The present study aimed to study the effectiveness of schema mode therapy on the increasing of explicit and implicit self -esteem in narcissistic personality disorder was carried out. In this study, the A-B single-subject design, and multiple baseline were used. The study sample was three clinic clients in Qazvin who were selected by purposive sampling. So that, the clients after answering to the Third Version of Millon Clinical Multiaxial Inventory (MMPI-III), were diagnostic interviewed by psychiatrist, and they were diagnosed with Narcissistic Personality Disorder (NPD). First, at baseline, subjects (2 female, 1 male), responded to the Rosenberg Self-Esteem Scale (RSES). After drawing the baseline data, the treatment process was followed in accordance with the principles of the single subject experimental designs and all three subjects entered to the treatment plan one after another. Schema therapy in 20 individual 60-minute sessions weekly for 2 sessions was administered and 1 month after the end of treatment, follow-up period followed. Finally, the data obtained using descriptive statistics, visual analysis charts with trend indicators, stability, percentage data unoverlapping (PND), and the percentage overlapping data (POD) were analyzed. The results showed that schema mode therapy on the increasing of the explicit self-esteem in narcissistic personality disorder was not effective, but on their implicit self-esteem was effective. According to the results, schema therapy on improving and increasing of the explicit self-esteem in narcissistic personality disorder is efficient and effective, and can be used in the treatment of symptoms that they are due to low implicit self-esteem in narcissism patients.