Background: Chronic rhinosinusitis is a very common disorder caused by chronic inflammation or irritation of nasal mucosa. Objectives: The purpose of this study was to evaluate the efficacy and safety of topical application of botulinum toxin type A (BTX-A) compared with intraturbinate injection for the treatment of noninfectious chronic rhinosinusitis. Patients and methods: This prospective comparative study was carried out on 30 patients with noninfectious chronic rhinosinusitis. Patients were divided randomly into two groups. BTX-soakedmerocel was applied topically in group A (topical group),which included 15 patients. Intraturbinate BTX injectionwas applied in group B (injected group),which included 15 patients. The total nasal-symptomscore (TNSS)was applied initially and after the procedure for 8weeks of follow-up period. Results: Both groups showed significant improvement of the TNSS all over the period of the study compared with the baseline, except at the eighth week in group A (topical group). At the eighth week, the TNSS was significantly higher in group A than group B, median (range) of 8 (4e11) compared with 5 (3e6), P value was less than 0.001. No one complained from epistaxis and only three patients in group B reported nasal-dryness sensation at the fourth and sixth weeks and improved by the eighth week. Conclusion: BTX-A topical application using soaked merocel could be a safe and a very successful way for managing the symptoms of chronic noninfectious rhinosinusitis. However, injections had a longer duration of impact than topical application.