Objective: To explore the association between the Lung Immune Prognostic Index (LIPI) and 1-year all-cause mortality in patients with idiopathic inflammatory myopathy related interstitial lung disease (IIM-ILD). Methods: Patients who were diagnosed with IIM-ILD at West China Hospital, Sichuan University from January 2008 to December 2021 were retrospectively included and categorized into three groups based on LIPI. Univariable and multivariable Cox proportional hazards models were conducted to explore potential association between the LIPI and patients' mortality. Results: A total of 1116 patients were screened, and 830 were included in this study. The multivariable Cox analysis showed that, compared with patients with poor LIPI, the hazard ratio (HR) for all-cause 1-year mortality was 0.22 (95% CI 0.05-0.93, P=0.04) for patients in the good LIPI group (LDH