The objective of this study was to investigate the effects on outcomes and morbidity of combining temperature-controlled radiofrequency (TCRF) tongue reduction with uvulopalatopharyngoplasty (UPPP) as an initial site-directed approach to the surgical treatment of obstructive sleep apnea syndrome (OSAS). This investigation was a prospective, nonrandomized, open-enrollment study of 20 consecutive eligible patients with OSAS. Seven patients had a single-level velopharyngeal obstruction (Fujita type I or IIa), and they were assigned to undergo UPPP only (group 1). Thirteen patients had a multilevel velopharyngeal and retroglossal obstruction (Fujita type IIb), and they were assigned to undergo TCRF tongue reduction in addition to UPPP (group 2). Patients who had only a retroglossal obstruction (Fujita type III) were not included in this study. Following their initial operation, nine patients in group 2 underwent two subsequent in-office TCRF tongue treatments under local anesthesia. Three patients in group 2 were lost to followup, and one patient underwent only one TCRF procedure at the initial operation; data on the latter patient are included in some of the outcomes measures reported here where indicated, but no data are reported on the three who were lost to followup. The primary post-treatment outcomes measures were the results of comparative polysomnography and clinician and patient evaluations regarding morbidity and symptom improvement. Analysis of these data showed that there was no difference between the two groups in terms of postoperative pain or dysphagia following the initial operative session. The degree of symptom improvement in the two groups was similar. Overall success rates--as measured by the apnea/hypopnea index (group 1: 57.1% success; group 2: 50.0%) and by the apnea index (group 1: 71.4% success; group 2: 70.0%)--were statistically comparable, given the small size of the sample (figures are based on 10 patients in group 2). The author concludes that combining TCRF tongue reduction with UPPP in patients with multilevel obstruction improves response rates to a degree that is comparable to that seen with UPPP alone in patients with single-level velopharyngeal obstruction. Moreover, the combination treatment does not increase the risk of additional pain, morbidity, and complications compared with UPPP alone.