Background <p>Systemic sclerosis (SSc)-associated interstitial lung disease (ILD) evolution is highly heterogeneous. Recent efforts to define progressive pulmonary fibrosis (PPF) have led to a definition including patient’s symptoms, pulmonary function tests, and high-resolution computed tomography (HRCT) criteria for progression, occurring over a one-year period (2022 ATS/ERS/JRS/ALAT Guidelines). For SSc-ILD, it has recently been proposed to apply these criteria without a time limit (2024 Guidelines). We aimed to determine the incidence of PPF in a cohort of SSc-ILD using 2022 Guidelines or 2024 Guidelines alternatively, and its impact on survival.</p> Methods <p>We conducted a retrospective single center study including patients with SSc-associated ILD diagnosed between 2006 and 2022, with at least one follow-up HRCT and concomitant PFT. All HRCT were centrally reviewed. PPF were defined according to 2022 and 2024 criteria, alternatively. Transplant-free and overall survival were compared using Cox regression models considering progression as a time dependent variable.</p> Results <p>Among 97 patients with SSc-associated ILD, 79 were included in the study, and a total of 279 HRCT were reviewed. The cumulative incidence of progression at 5 years from ILD diagnosis was 22.7% using a 1-year limited definition (2022 criteria) and 45.6% using a definition with no time limit (2024 criteria). Transplant-free survival and overall survival were significantly altered in the group of patients who met 2022 criteria (short-term progressors), in contrast to slow progressors (fulfilling the 2024 criteria but not meeting the 2022 criteria), whose survival did not differ significantly from that of non-progressors.</p> Conclusion <p>Our findings suggest that short-term and slow progressions have distinct prognostic implications and may require dedicated therapeutic management.</p>