Because respiratory complications arising from common anxiety medications may contraindicate pharmacological intervention in patients with asthma, behavioral intervention is a vital component of treating anxiety successfully in these patients. Previous research suggests behavioral treatment may reduce panic symptoms and asthma medication use while subsequently increasing quality of life in patients with asthma and panic disorder; however, research assessing treatment outcomes of this population remains limited. A 16-year-old male, “Mark,” was referred for psychological services regarding concerns about a high frequency of asthma attacks and anxiety surrounding these attacks. Mark met diagnostic criteria for the Diagnostic and Statistical Manual for Mental Disorders-Fourth Edition (DSM–IV) panic disorder without agoraphobia, mental disorder (panic disorder) affecting asthma, and generalized anxiety disorder. Treatment consisted of psychoeducation, progressive muscle relaxation, guided imagery, cognitive restructuring, problem-solving training, interoceptive exposure, and relapse prevention training. At treatment termination and 2-year follow-up, Mark displayed clinically significant reductions in depressive and anxious symptoms, reported no further occurrences of panic attacks, and no longer required routine psychotropic or asthmatic medications. Therefore, Mark's posttreatment diagnosis was panic disorder without agoraphobia, in full remission; he no longer met criteria for diagnoses of mental disorder (panic disorder) affecting asthma or generalized anxiety disorder. These findings support the claim that behavioral treatment effectively reduces anxiety and asthma symptoms in patients with panic disorder and asthma, and suggests that targeting psychological concerns can significantly impact physical health.