This case study was to describe the process of intervention of cognitive-behavioral therapy to verify the effectiveness on the comorbidity of a recurrent major depressive disorder and obsessive-compulsive personality disorder. The subject of study was a psychological private researcher patient, an adult male of 66 years, abroad with doctoral studies, pensioned and married 30 years ago. The evaluation used techniques and instruments that allowed to confirm the diagnosis as are: clinical interview, registration of dysfunctional thoughts, direct behavioral observation, BDI, BAI, EMT, CIE, MCMI-II, IPA, as well as statistics Student's T test and Pearson for of data analysis. In the results, there are presented a detailed description of the configuration and conceptualization of comorbidity between depression and the TOCP, the design of the intervention plan based on the principles of cognitive-behavioral model to work on the comorbidity and the impact of the intervention plan in the recovery of the patient’s symptoms. It was concluded that in the course of the session, both the TOCP and depression remained constant, without significant variations during the treatment, possible explanations in this regard argue in the deep-rooted patterns that the patient presents, the intermittency of the session and to the difficulty of intervening in an important factor in maintenance of the symptoms, which is environment in which the patient lives and thrives.