We conducted a survey to detect diabetes and hypertension in 4 villages and 5 adjacent camps in Raichur district, Karnataka state in South India where two heterogenous populations co-exist; the indigenous population and migrants who originally came from villages in Andhra Pradesh state. The staple diets of these populations differ: migrants consume rice while the indigenous populations consume millets. Diabetes was confirmed by blood glucose testing. Blood pressure was recorded using a mercury sphygmomanometer. In adults above the age of 30 years the prevalence of diabetes mellitus was significantly higher in the rural-rural migrants (9.1%; n = 529) than the indigenous population (2.2%; n = 765), (x2 = 30.8; P < 0.001). Hypertension was diagnosed in 29.1% of the migrants and 13.9% of the indigenous population (x2 = 45.3, P < 0.001). Obesity was found more frequently in the migrants. It was concluded that i) transrural migrant populations have a high prevalence of diabetes and hypertension and ii) the significant inter-population differences may be due to the higher frequency of risk factors in the migrants whose dietary habits also differed from the indigenous populations.