There is a great deal of research revealing how asthma is influenced by psychological variables such as symptom perception and negative emotions. Psychologically based treatments including biofeedback, yoga, hypnosis, stress management, relaxation and guided imagery, and written-emotional expression have all been effective in improving pulmonary lung function and overall quality of life. It has been estimated that asthma affects approximately 6 million children under the age of 18. The ramifications for this population include increased absenteeism, restriction of activities, and poor peer relationships. Therefore, students with asthma often require school psychological services. This study used a multiple baseline design across 4 participants in order to replicate written emotional expression as an intervention to improve lung functioning, quality of life, and negative emotions in elementary, middle, and high school students with asthma. Calibrated spirometry was used to assess the predicted forced expiratory volume in 1 second (FEV1 measure of large airway functioning) and forced expiratory flow (FEF[25-75] measure of small airway functioning). In addition, state and trait anxiety, happiness and life satisfaction were measured. Results indicated that both lung functioning and perceptions of quality of life were positively affected.