We report a case of a 27-year-old woman with panic attacks which began one and a half year before coming to therapy and worsened in the prior month of consultation. After four assessment sessions and an interview with a friend, a diagnosis of social anxiety disorder was made. Panic attacks were triggered by social situations and the patient was afraid of vomiting in front of the others and being evaluated negatively. A cognitive-behavioral treatment was applied over 21 sessions which included self-monitoring, training in controlled breathing, attention training, cognitive restructuring, self-exposure in vivo and assertiveness training centered on her partner, since patient's anxious symptomatology was also related to the discussions and mistreatments by her companion. Scores on the scales applied along the process indicated a progressive and clinically significant improvement. The main reasons that may have contributed to therapeutic success are the motivation for change, the strong therapeutic alliance established, the acceptance and consistent application of the exposure technique, and the assertiveness training related to her partner