Objective:To study the incidence, treatment, and outcomes of adenocarcinomas of the nose and paranasal sinuses over the last 15 years.Design:Retrospective chart review of 20 patients identified and treated at the otolaryngology clinic of Zurich University Hospital between 1992 and 2007.Main Outcome Measures:Recurrence- and disease-free survival were the most important outcomes of interest.Results:Twenty patients (16 men) with sinonasal adenocarcinoma were found. The average age was 64 years. At the time of diagnosis, usually more than one sinus was involved and nasal obstruction was the most common symptom. In 57.9% of patients, the initial treatment was endoscopic surgery. Two-year recurrence-free survival was 48.5%, and 5-year disease-specific survival was 77.8%.Conclusions:Surgical resection is difficult owing to anatomic restraints, and adjuvant therapy must be considered in most patients. Endoscopic surgery was performed in a majority of patients, with outcomes comparable to those in the general literature.Significance:Adenocarcinoma of the paranasal sinuses was found to have almost 80% 5-year survival if adequately treated surgically and with adjuvant intensity-modulated radiotherapy.