Sinusitis is the most commonly reported chronic disorder in America. More than 75,000 sinus surgical procedures were performed in 1993. Evaluating the appropriateness of procedures is a major focus of health care reform. The American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) collaborated with Value Health Sciences, Inc. (VHS) to develop guidelines for the use of sinus surgery. The clinical utility of these guidelines is presented. Patients undergoing sinus surgery at Barnes Hospital in St. Louis, Missouri, between November 1994 and July 1995 were eligible. Relevant patient information was used to prospectively rate surgery on the nine-point VHS appropriateness scale (1 to 3, inappropriate; 4 to 6, equivocal; 7 to 9, appropriate). Of 55 patients, 37 (67%) had chronic sinusitis, 10 (18%) recurrent sinusitis, five (9%) chronic sinusitis with nasal polyps, and three (6%) sinusitis with moderate to severe asthma; 27 (49%) had previous sinus surgery. Appropriateness ratings ranged from 1 to 9, with nine (16%) procedures rated as inappropriate, 22 (40%) uncertain, and 24 (44%) appropriate. There were no significant differences in the ratings of appropriateness between the group of patients who had undergone previous sinus surgery and the group of patients who had not. Overall, the guidelines were easily applied and clinically pertinent.