Objective This study aims to analyze the clinical characteristics of idiopathic inflammatory myopathy (IIM) associated interstitial lung disease (ILD) with positive anti melanoma differentiation-associated gene 5 (MDA5) antibody. Methods The clinical data of 91 patients with IIM in Shanxi Bethune Hospital from Jan 2019 to Mar 2022 were collected. Then various comparisons and analyzed retrospectively in the clinical symptoms, laboratory indicators and imaging characteristics between the negative MDA5-IIM and the positive anti-MDA5-IIM. ResultsCompared with the negative anti-MDA5-IIM patients, the significantly higher incidences of Gottron sign (71.0% vs. 38.3%), ulcerative rash (45.2% vs.16.7%), dyspnea (64.5% vs. 36.7%), and ILD (71.0% vs. 43.3%), in the positive anti-MDA5-IIM patients (P<0.05). Compared with the negative anti-MDA5-IIM patients, the more ground-glass opacification (GGO) in the positive anti-MDA5-IIM patients on high resolution computed tomography (81.8% vs.53.8%, P<0.05). Compared with the positive anti-MDA5-IIM patients without ILD, the positive anti-MDA5-IIM patients with ILD had significantly higher incidence of Gottron sign (77.3% vs. 33.3%), the increased levels of lactate dehydrogenase [(525.20±203.09) IU/L vs. (321.73±188.88) IU/L], Krebs von den Lungen-6 [(1399.55±869.64) U/mL vs. (371.56±128.92) U/mL], and D-dimer [(1226.65±902.31) U/L vs. (703.73±160.11) U/L], as well as higher positive rate of anti-Ro-52 antibody (68.2% vs. 22.2%) and the higher case fatality rate (54.5% vs. 0.0%), with all P<0.05. The triple treatment of high-dose glucocorticoid (GC) combined with intravenous cyclophosphamide (IVCY) and another immunosuppressive agent (tacrolimus or tofacitinib) was found to be effective in the MDA5-IIM associated ILD group, with a lower case fatality rate (28.6%) than high-dose GC combined with IVCY group (47.1%). Conclusions The positive anti-MDA5-IIM with ILD of patients have the higher incidence of rash and dyspnea, with GGO as the most common imaging manifestation. When rapidly progressive interstitial lung disease (RPILD) is combined, the case fatality rate higher. Meanwhile, early intensive immunosuppressive therapy may improve the survival rate of RPILD patients with positive anti-MDA5 antibody.