Background and Clinical Significance: Connective Tissue Disease-Associated Interstitial Lung Disease (CTD-ILD) is a collection of systemic autoimmune disorders resulting in lung interstitial abnormalities or lung fibrosis. CTD-ILD pathogenesis is not well characterized because of disease heterogeneity; Case Presentation: A 67 years old female presented to the hospital through outpatient clinic with dyspnea for almost 3 – 4 months, patient underwent DLCO, HRCT and blood test such as ANA IF, RF, ANA profile, Myositis panel and KL-6 and diagnosed CTD-ILD based on findings. Patient has positive ANA IF, positive Ro-52, and PL-12 autoantibody also high concentration of KL-6 which is suggestive to CTD-ILD. HRCT result also support CTD – ILD with indeterminate UIP pattern; Conclusions: HRCT is one of gold standard in establishing diagnosis of CTD-ILD and KL-6 can help early detection and diagnosis of CTD-ILD. © 2025, Perinatal Medicine Foundation. All rights reserved.