Dual energy computed tomography (DECT) lung perfusion is an encouraging option for early diagnosis of ILD with adequate accuracy, particularly in differentiation of UIP from non–UIP pathologies. Clinically Suspected cases of DILD aged 30–70 years were included . All the patients underwent blood investigations and pulmonary function test . DECT Somatom force machine was used for perfusion analysis . Final diagnosis was achieved by combining histopathology and findings of clinicoradiological follow up. Diagnostic efficacy of DECT perfusion was evaluated in terms of sensitivity, specificity, positive predictive value, negative predictive value and accuracy.Total 45 patients with mean age of 55.60+6.95 years were enrolled in the study. DECT perfusion was found to be 93.3 % accurate, 92.6% sensitive, 94.4% specific had 96.2% positive predictive value and 89.5% negative predictive value to diagnose the patients of UIP