['Nasal polyposis is an inflammatory disease of unknown etiology. This study aimed to evaluate the effect of a short course of oral prednisone followed by intranasal budesonide on nasal symptoms, polyp size, nasal flow, and computed tomography scan.', 'Eighty-four patients with severe nasal polyps were included. After a steroid washout period, patients were randomized into two groups: group A (n = 63) received oral prednisone for 2 weeks and group B (n = 21) did not receive any steroid treatment. Patients from group A received intranasal budesonide for 12 weeks.', 'Atopy was positive in 36.8% of patients. Blood eosinophilia was higher in asthmatic (7.2 +/- 0.7%, P < .05) than in nonasthmatic (3.0 +/- 0.4%) patients. Asthmatic patients showed higher scores on nasal obstruction and loss of smell than nonasthmatics. Oral steroids caused a significant improvement in all nasal symptoms and improved polyp size (2.1 +/- 0.1, P < .05) and nasal flow (560 +/- 35 cm/s, P < .05) compared with nontreated patients (2.8 +/- 0.1 and 270 +/- 34 cm/s, respectively). Intranasal budesonide maintained the improvement on nasal symptoms, polyp size, and nasal flow. Steroid treatment reduced the computed tomography scan score (15.4 +/- 1, P < .05) compared with before treatment (18.2 +/- 0.8).'] Is a short course of oral prednisone followed by intranasal budesonide an effective treatment of severe nasal polyps?