Introduction: Alopecia areata (AA) is an immune-mediated disease characterized by non-scaring hair loss. High levels of FABP4 have been implicated in different inflammatory diseases. We aim to assess and correlate the level of FABP4 in AA patients and compare with healthy controls. Methods: Eighty-Eight subjects enrolled subdivided equally into AA and healthy controls. AA patients were classified according to the severity and pattern of the disease. The concentration level of FABP4 in serum was assessed and compared to healthy controls using ELISA. Results: The level of FABP4 tends to increase in AA patients than controls with a significant difference (p = 0.0001).There were no statistically significant differences between FABP4 and gender, history, family history, related diseases, or prior treatments. There is a high significant difference between patients with relapse and progressive patients with p = 0.037. Also patients with positive effects in other body sites have higher FABP4 levels than patients without infection in other sites with p = 0.05. The level of FABP4 tends to increase with the severity of the patients. Findings show that there are positive correlations between FABP4 and (disease duration; number of attacks; SALT Score) with r = 0.45, p = 0.0021; r = 0.41, p = 0.007, and r = 0.88, p < 0.0001, respectively. Conclusion: Elevation of FABP4 in serum may correlate with disease severity and could play a vital role in the diagnosis of AA.