Objectives: To evaluate the role of the topical corticosteroid, mometasone furoate, nasal spray in the treatment of post COVID-19 anosmia. Methods: A prospective, randomized, controlled trial was conducted among patients with post COVID-19 anosmia. One hundred patients were randomly assigned to two groups; group I included 50 patients received mometasone furoate nasal spray in an appropriate dose of 2 puff (100 μg) once daily in each nostril for 3 weeks with olfactory training, group II included 50 patients were advised to keep on olfactory training only. The assessment of smell was done using (Visual Analog Scale from 0 to 10). All patients were initially evaluated after their recovery from COVID-19 and followed up for 3 weeks. The smell scores were recorded weekly and the duration of smell loss was recorded from the onset of anosmia till the full recovery. Results: In both groups, the smell scores significantly improved by the end of the third week (P < 0.001). By comparing smell scores between both groups after 1 week, 2 weeks, and 3 weeks of treatment, there were no statistically significant differences between both groups. In group I, (62%) of patients completely recovered their sense of smell after 3 weeks of treatment, compared to (52%) of patients in group II (P = 0.31). Conclusion: The results suggested that using mometasone furoate nasal spray as a topical corticosteroid in the treatment of post COVID-19 anosmia offers no superiority benefits over the olfactory training, regarding smell scores, duration of anosmia, and recovery rates. Trial registration: ClinicalTrials.gov ID: NCT04484493