To conduct the first prospective, randomized, controlled trial evaluating and comparing the medical and surgical treatment of polypoid and nonpolypoid chronic rhinosinusitis (CRS). Ninety patients with CRS were equally randomized either to medical or surgical therapy. All patients underwent pre- and posttreatment assessments of visual analogue score (VAS), the Sinonasal Outcome Test-20 (SNOT-20), the Short Form 36 Health Survey (SF-36), nitric oxide (NO), acoustic rhinometry, saccharine clearance time (SCT), and nasal endoscopy. Each patient had three assessments: before starting the treatment, after 6 months, and, finally, after 1 year. Both the medical and surgical treatment of CRS significantly improved almost all the subjective and objective parameters of CRS (P <.01), with no significant difference being found between the medical and surgical groups (P >.05), except for the total nasal volume in CRS (P <.01) and CRS without polyposis (P <.01) groups, in which the surgical treatment demonstrated greater changes. CRS should be initially targeted with maximal medical therapy (e.g., a 3 month course of a macrolide antibiotic, douche, and topical steroid), with surgical treatment being reserved for cases refractory to medical therapy. The presence of nasal polyps is not a poor prognostic factor for the efficacy of CRS therapy, either surgical or medical.