We conducted a retrospective study to determine the prevalence of Samter's triad (nasal polyps, asthma, and aspirin sensitivity) in 208 consecutively presenting patients who had undergone functional endoscopic sinus surgery (FESS) for chronic rhinosinusitis from September 2001 through August 2003. Overall, Samter's triad was found in 10 patients (4.8%); subgroup analyses showed that the prevalence of Samter's triad was 5.9% in adults, 9.4% in patients with nasal polyps alone, 16.9% in patients with asthma alone, and 25.6% among patients with both polyps and asthma. On average, patients with Samter's triad had undergone approximately 10 times as many previous FESS procedures as had the patients without Samter's triad (mean: 5.2 vs. 0.53; p < 0.001). In addition to Samter's triad, four other factors were independently and significantly associated with a higher number of previous FESS procedures: nasal polyps alone, asthma alone, both polyps and asthma, and cystic fibrosis alone. Finally, at 6 months following their most recent surgery, patients with Samter's triad had significantly higher rates of symptom recurrence (nasal obstruction, facial pain, postnasal drip, and anosmia) and a recurrence of nasal polyps.