Antisynthetase syndrome (AS) is a rare autoimmune disease characterized by autoantibodies against aminoacyl-transfer RNA synthetase and clinical features which can include interstitial lung disease (ILD). Current available evidence of treatment is based on expert opinions and case reports. Here, we present a patient with an initial diagnosis of eosinophilic pneumonia, who was later diagnosed with anti-PL7 antisynthetase syndrome with ILD and eosinophilic inflammation. The patient was non-responsive to classic immunosuppressants but responded remarkably well to intravenous immunoglobulin.