Background and aims: This 3-year prospective study aimed to identify baseline parameters that predicted the progression of carotid-femoral pulse wave velocity (cf-PWV), which was used to evaluate aortic stiffness, among Singapore's multi-ethnic Asians with type 2 diabetes (T2DM). Methods: The cf-PWV was measured by the gold-standard tonometry method in 994 T2DM subjects at baseline and follow-up. The annual rate of cf-PWV change was calculated, and individuals above the 90th percentile with rate >= 1.42 m/s per year were regarded as rapid progressors (n = 104). In a subgroup analysis of subjects with normal cf-PWV at 1st visit (n = 611), incident aortic stiffness was defined as follow-up cf-PWV >= 10 m/s (n = 188). Results: The total cohort (mean age: 57 +/- 10 years; 53.4% Chinese, 20.4% Malay, 22.9% Indian, 3.2% 'Others') displayed a median annual cf-PWV progression rate of 0.2 m/s. Adjusted multivariate regression analyses showed that baseline age, cf-PWV and body mass index (BMI) constantly predicted follow-up cf-PWV, annual cf-PWV progression rate, rapid cf-PWV progression, and incident aortic stiffness. Paradoxically, lower baseline cf-PWV was associated with elevated annual cf-PWV progression rate and rapid progressors. This inverse relationship remained significant across ethnicities after ethnic stratification. Higher BMI independently predicted cf-PWV progression in Chinese and Indians, but not in Malay and 'Others' ethnic groups. Increased age was a significant predictor in Chinese and 'Others' ethnicities. Conclusions: We demonstrated that baseline BMI is a modifiable independent risk factor of cf-PWV progression and incident aortic stiffness. Therefore, better obesity management may impede aortic stiffness in Singapore's T2DM patients, especially in the Chinese and Indians. (C) 2017 Published by Elsevier Ireland Ltd.