One hundred seven known aspirin (ASA)-sensitive patients with rhinosinusitis-asthma were studied from 1975 to 1988. Forty-two of the patients avoided ASA and served as the control group. Thirty-five patients were desensitized to ASA and treated with daily ASA treatment (Rx) for as long as 8 years (mean, 3.75 years) to May 1988 and were designated the continuous group. Thirty patients, initially desensitized to ASA and treated with daily ASA, who stopped Rx permanently after a mean duration of 2 years, were designated the discontinued group. Retrospective analyses of baselines revealed that both continuous and discontinued groups during ASA Rx demonstrated statistically significant reduction in number of hospitalizations per year, emergency room visits per year, outpatient visits per year, upper respiratory infections-sinusitis-antibiotics per year, need for nasal polypectomies and additional sinus operations, and improvement in sense of smell compared to the control group. Simultaneously, the ASA-Rx groups were able to significantly reduce systemic corticosteroid dosage, corticosteroid bursts per year, and, in the continuous group only, significantly reduce inhaled corticosteroids. All three groups maintained control of respiratory symptoms. ASA desensitization followed by long-term daily ASA Rx appears to improve ASA-sensitive rhinosinusitis-asthma and concomitantly allows reduction of systemic corticosteroids.