The aim of the present study was to determine the effectiveness of MBT and attachment-based therapeutic model on the symptoms of grandiosity and lack of empathy in people with narcissistic personality disorder. The research method was a quasi-experimental design with a pre-test-post-test control group design. The population of the present study included all patients with narcissistic personality disorder in Mashhad who had referred to the dynamic psychology clinic in Mashhad from 1402-1403 with a referral from a psychiatrist. Using purposive sampling, 30 people were selected as a sample and randomly assigned to two groups (15 experimental, 15 control). Data collection tools included the Emotional Empathy Questionnaire (Mehrabian and Epstein, 1972) and the Magnifying Fantasies component of the Morbid Narcissism Questionnaire (Pinks et al., 2009). The mentalization-based (MBT) and attachment-based therapeutic model protocol was implemented in the experimental group during 12 90-minute sessions, once a week. The results of the analysis of covariance showed that by controlling for the pre-test effect, there was a significant difference between the mean post-test empathy and the magnification syndrome in the experimental and control groups (P<0.05). From the above findings, it can be concluded that the mentalization-based therapy (MBT) and attachment model were effective on the empathy process and the magnification syndrome of people with narcissistic personality disorder.