This study tested the efficacy of a nurse-administered 8-week group treatment program for adults with asthma suffering from coexisting panic disorder. The program consisted of cognitive behavioral treatment (CBT) for panic disorder combined with asthma education (AE). Forty-eight women with a confirmed diagnosis of asthma and panic disorder were randomly allocated to a treatment condition (n=25) and a wait-list control condition (n=23). Twenty-five participants--15 in the treatment group and 10 in the wait-list control group--completed treatment. Repeated measures ANOVA procedures were used to compare the groups on panic and asthma outcomes at posttreatment and 6-month follow-up. The results demonstrate that the CBT-AE program is capable of producing substantial and durable antipanic and antianxiety treatment effects and led to substantial but nonsustained improvement in morning peak-flow expiratory rate and asthma-related quality of life. Implications of these findings for this clinical population are addressed.