BACKGROUND: For more than 70 years, the coexistence of asthma and paranasal rhinosinusitis has been noted in the medical literature. Causal relationships have been proposed but not proved. To date, limited evidence exists suggesting that asthma improves after surgical correction of rhinosinusitis. OBJECTIVE: To determine whether asthma control improved after first-time functional endoscopic sinus surgery (FESS). PATIENTS AND METHODS: A retrospective medical record analysis was performed on 13 patients with chronic bronchial asthma who underwent FESS for medically refractory chronic rhinosinusitis. Patients received comprehensive asthma care before and after FESS (mean, 19.3 and 33.1 months, respectively). Outcomes analyzed included pre- and post-FESS individual and group mean asthma symptom scores, medication use scores, pulmonary function test results, and emergency department visits or hospital admissions for asthma. Patient medical records were obtained from a private allergy-immunology practice affiliated with a medical school. The surgical procedure was performed at a tertiary care teaching hospital by a single ear, nose, and throat surgeon (R.L.). RESULTS: Following FESS, there was no statistically significant change in group mean asthma symptom scores, asthma medication use scores, pulmonary function test results, and the number of emergency department visits or hospital admissions. Only a few patients demonstrated statistically significant improvement after FESS in asthma symptom scores (1 patient), medication use scores (1 patient), or pulmonary function test results (2 patients). CONCLUSIONS: The data do not support the hypothesis that first-time FESS for medically refractory chronic rhinosinusitis in adult patients with chronic asthma leads to reduced postoperative asthma symptoms or asthma medication use or improved pulmonary function. Based on this limited study, a reexamination of the benefits of sinus surgery to coexisting asthma is in order.