The goal of this study was to evaluate the efficacy of cognitive-behavioral therapy for comorbid panic disorder with agoraphobia (PDA) and generalized anxiety disorder (GAD) by combining treatment strategies for both disorders. A single-case, multiple-baseline design across participants was used. Three participants with primary PDA and secondary GAD took part in the study. The efficacy of the treatment was assessed by means of a structured interview, self-administered questionnaires, and daily self-monitoring measures. After treatment, 2 of the 3 participants achieved high end-state functioning and maintained this level of functioning at 3-, 6-, and 12-month follow-ups. The third participant also improved but only reached high end-state functioning at 6-month follow-up. It therefore appears that the combined treatment is relatively effective for PDA-GAD comorbidity. Possible avenues for improving the treatment are suggested.