We conducted a retrospective review of 145 consecutively presenting adults treated for chronic rhinosinusitis (CRS) in a tertiary care institution. Our goals were to determine (1) the prevalence of asthma in these patients, (2) the prevalence of specific CRS symptoms in both asthmatic and nonasthmatic patients, and (3) the frequency of surgical treatment for CRS in patients with and without asthma. We found that asthma was present in 23.4% of CRS patients, a much higher rate than the 5% prevalence of asthma in the general adult population. Patients with asthma had a significantly higher prevalence of nasal polyps (47 vs. 22%; p = 0.004), olfactory dysfunction (26 vs. 6%; p = 0.001), and nasal congestion (85 vs. 60%; p = 0.027) than did those without asthma. Patients without asthma had a significantly higher prevalence of headache (72 vs. 53%; p = 0.037) and rhinorrhea (58 vs. 38%; p = 0.047). The prevalence of postnasal drip and environmental allergies in the two groups was similar. Although the difference between the proportions of patients with and without asthma who required primary sinus surgery was not statistically significant (76 vs. 64%; p = 0.175), patients with asthma did require significantly more revision sinus procedures overall (mean: 2.9 vs. 1.5; p = 0.003).