Knowledge of the diagnosis and treatment of sinusitis is essential to the care of the patient with asthma. Interest in the association of this disease and bronchial asthma has been renewed during the past decade, although it had been recognized for years. Sinusitis is more common in subjects with asthma, especially those with the aspirin triad (aspirin intolerance, asthma, and nasal polyps). Proper treatment by medical and/or surgical means will frequently result in significant improvement of asthma.