A 63-year-old man was transferred to our hospital with fever, cough, and dyspnea. Three months prior to admission, he had developed edema of both upper eyelids. On admission, in addition to typical cutaneous lesions, chest computed tomography showed diffuse ground glass attenuation and consolidation of bilateral lungs. He was diagnosed with rapidly progressive interstitial lung disease complicated by dermatomyositis. Despite immediate immunosuppressive therapy, he died on day 5 due to respiratory failure. The anti-MDA5 antibody had increased to 4,650 index. He was diagnosed with immune thrombocytopenia (ITP) because of severe thrombocytopenia 5×10³/μL on admission, bone marrow aspiration, and elevated platelet-associated immunoglobulin G. Anti-MDA5 antibody-positive interstitial lung disease may be accompanied by ITP. We should consider ITP as a comorbidity when we encounter cases with anti-MDA5 antibody-positive interstitial lung disease accompanied by thrombocytopenia.