Background: Alopecia areata (AA) is a disease characterized by the hair loss sharply limited in any part of the body, especially on the scalp, in circular or oval areas. The purpose of this study is to search the serum paraoxonase 1 (PON1), arylesterase and oxidative status with serum prolidase activities in people with AA. Methods: The study included 60 AA and 50 healthy control subjects. In both groups, serum PON1, prolidase, arylesterase activities, total oxidative status (TOS) and total antioxidant capacity (TAS) levels and oxidative stress index (OSI) were calculated. Results: TOS, OSI levels and prolidase activity in patients with AA were found to be significantly higher compared to the control group (p = 0.02, p = 0.004, p < 0.001, respectively), whereas PON1 and arylesterase activities were significantly lower (p < 0.001, p = 0.005, respectively). There was no difference in serum TAS levels between the two groups. Conclusion: This comprehensive work shows that the role of oxidative stress is very important in the pathogenesis of AA. In this study, we believe that we clarified the pathogenesis of oxidative stress for AA patients by investigating the TAS, TOS, OSI levels, PON1, arylesterase and prolidase enzyme activity parameters.