The goal of this study was to evaluate the efficacy of a cognitive-behavioral treatment package for comorbid generalized anxiety disorder (GAD) and panic disorder with agoraphobia (PDA). A single-case, multiple-baseline, across-subjects design was used with 3 primary GAD patients with secondary PDA. The efficacy of the treatment was evaluated with a structured interview, a battery of self-report questionnaires, and daily self-monitoring booklets. Results are promising: At posttreatment, 2 out of 3 participants achieved high endstate functioning and maintained this level at 3-, 6-, and 12-month follow-ups. The 3rd participant also improved but achieved moderate endstate functioning. The strengths and limitations of the treatment are discussed. (Contains 1 note, 2 tables, and 3 figures.)