Background: Alopecia Areata (AA) is common autoimmune disease. Many therapeutic options have been used by dermatologists, but none are curative or preventive. Bimatoprost is an analogue of Prostaglandin F2α (PG F2 α) which is used to treat glaucoma. Increase in eye lash number, thickness and pigmentation have been reported as bimatoprost side effect. Objectives: To evaluate the efficacy and safety of bimatoprost 0.03% solution in treatment of scalp AA in comparison to topical corticosteroid as a well established treatment for AA.Patient and Methods: This prospective comparative randomized single blinded clinical trial included twenty adult patients with Patchy AA lesions. Two AA patches of the scalp were randomly assigned in each patient to treatment by either topical corticosteroid cream (group A) or bimatoprost solution (group B) for a period of 3 months. All patients were assessed by a fixed blinded senior physician. The assessment was performed by comparing serial photographs of all patients at base line, when hair regrowth first occurred (initial response) and at the end of treatment period (3 months). The percent of hair regrowth was calculated using SALT score system for hair regrowth. In addition, all patients were examined at regular monthly intervals by the same physician for the occurrence of side effects.Results: There was statistically significant difference between the two groups regarding the percentage of hair regrowth (P value= 0.001), the onset of initial response (P value =0.005) and the occurrence of side effects (P value=0.001). On the other hand, there was no statistically significant difference in the reduction of SALT score after therapy between both groups. Conclusion: Bimatoprost represents a potentially effective and safe therapeutic option for scalp AA with comparable result to the well established treatment (topical corticosteroid).