Eosinophilic fasciitis is a rare connective tissue disease characterized by increased levels of peripheral blood eosinophils and infiltration in the myofascia. The diagnosis of eosinophilic fasciitis is primarily based on clinical manifestations, laboratory tests, and pathological biopsy, with the exclusion of other possible causes of fasciitis and eosinophil increase. Herein, we report a case of postnatal eosinophilic fasciitis occurring in a woman in her 20s, who developed the condition in her right forearm. The patient, who was postpartum, showed considerable recovery after conservative treatment with the corticosteroid prednisone.