Type 2 Diabetes Mellitus (T2DM) is a chronic disease with increasing prevalence throughout the world. Almost every system of the body is affected by the disease [1-3]. Pulmonary function impairment has also appeared to be a complication of diabetes [4,5]. The aim of this study is to develop a statistical model as a primary prevention tool which can predict pulmonary function indices in diabetic individuals at an early stage in situations where spirometry is not possible because of any means. 73 Diabetics and 77 age matched Non Diabetics’ individuals, who were non smokers and had no apparent pulmonary diseases were recruited. All subjects underwent screening with detailed history, anthropometry, HbA1c and spirometric measurements. There was a significant reduction in the Force vital capacity (FVC) [mean difference (95% CI) 0.495L (0.27, 0.72) P < 0.001], Force expiratory volume in first second (FEV1) [mean difference (95% CI) 0.34L (0.15, 0.53) P < 0.001] and FEV1/FVC ratio [mean difference (95% CI) -0.018 (-0.036, -0.0003) P ≤ 0.05] in the diabetic subjects as compared to the healthy individuals. A model was built using multivariable regression analysis to predict FVC with adjusted R2 value of 0.778. The model equation is as follows. FVC = β0 + β1(X1) + β2(X2) + β3(X3) + β4(X4) + β5(D1) + β5(D2). Whereas, β0 = -2.78 (constant), X1=gender, X2=height, X3=age, X4=HbA1c, D¬ = duration of disease >10years. Female gender taken as reference, Duration of disease: ≤5 years (reference), 6 – 10 years (non significant) & > 10 years T2DM individuals had subclinical lower FVC and FEV1 as compared to the non diabetics. The effect on the FVC was even more pronounced in diabetics who had inadequate glycemic control and prolonged duration of disease. Therefore, regular assessment of the diabetic patients for the subclinical pulmonary function impairment should be done either through spirometry or from the statistical model derived above so as to prevent the respiratory complications that may follow later.