Background: Alopecia areata is an autoimmune disorder caused by a breakdown in the follicular immune privilege system, resulting in non-scarring hair loss. Many therapeutic options have been tested with variable results. 
Aim of the work: To assess the efficacy of trichloroacetic acid [TCA] 35% in patients of alopecia areata.
Patients and Methods: This prospective cross-sectional study included 40 patients recruited from department of dermatology and venereology, Al-Hussein hospital. Every patient was treated by 3 sessions of TCA 35% with one-month intervals. The assessment was done by clinical, trichoscopy, and histopathological examination.
Results: The study included 40 patients, 22 males [55%] and18 females [45%]. The mean age of studied patients was 25.6 ± 8.6 years with a minimum age of 16 years and a maximum age of 50 years. The duration of the disease ranged between 2 months and 10 years with a mean duration of 2.7 ± 2.5 years. Thirty patients [75%] showed improvement at the end of TCA sessions.
Conclusion: Based on our findings, topical application of TCA 35% is a safe and effective treatment option for patients with alopecia areata. Moreover, it can be used in wide areas of the scalp and cases of alopecia totalis.