Twenty asthma patients who underwent functional endoscopic sinus surgery for chronic sinusitis were studied. Medical records and questionnaire data for these 20 patients were studied regarding the impact of sinus disease and functional endoscopic sinus surgery on their asthma. We found that 95% reported that their asthma was worsened by their sinus disease (95% confidence interval, 0.74 to 0.99+), and 85% reported that functional endoscopic sinus surgery improved their asthma (0.60 to 0.97). Of the 13 patients who used both inhalers and systemic medication, 53.8% were able to eliminate some of their medication (0.21 to 0.79). Furthermore, 61.5% of these patients had a concomitant reduction in their inhaler use (0.28 to 0.85). All patients (six) who used only inhalers experienced a reduction in their inhaler use (0.54 to 1.00), and two patients were able to eliminate their inhalers completely. One of two patients who were steroid dependent was able to discontinue steroids after surgery. Of patients who used steroids intermittently (13), 53.8% were able to eliminate the use of steroids after surgery (0.21 to 0.79). Patients who required preoperative hospital admissions (4) and emergency room or urgent physician office visits (18) had a 75.0% and 81.3% (p < 0.001) reduction in visits, respectively, after surgery. Because 43% of the cost of asthma is the result of hospitalizations and emergency department/urgent physician office visits, a significant impact on health care costs can be realized with functional endoscopic sinus surgery in this patient population.