The purpose of this study was systematically to evaluate the effectiveness of several modes of psychological intervention used with male asthmatic children being treated in the Allergy Outpatient Clinic. Therapeutic effectiveness was measured by large airway changes in respiratory function, and the number of recurrent asthmatic attacks. The psychotherapeutic modes used were Relaxation Training, Assertive Training, and combined Relaxation plus Assertive Training. All patients were administered medication by the responsible physician. The group psychotherapy experiences were controlled by using patients who received medication alone and by patients who received medication and met in a leaderless group. The effectiveness of the therapeutic interventions was determined by comparisons between pretreatment measures and measurements taken during and after the eight-week treatment program. Both Relaxation Training by itself and combined Relaxation plus Assertive Training increased respiratory functioning and reduced the number of attacks. Assertive Training alone failed to improve respiratory function and had a tendency to increase the frequency of asthmatic attacks. It was concluded that the most effective management in male asthmatic children was achieved by the combination of medical and psychological treatments.