In developing countries the prevalence of diabetes mellitus is reported to be lower in rural areas compared to urban areas. This difference has been attributed to lifestyle factors associated with the higher socio-economic status of those living in urban areas. However, recent clinical observations indicate that the prevalence of diabetes is on the increase even in the rural sector. The aims of the present study were to objectively assess whether the prevalence of diabetes has increased in a named rural community in Sri Lanka during a period of ten years and whether there has been a change in the socio-economic status of the community during this period. The study was conducted on a sample of 220 subjects randomly selected from an adult population of 25,605 residents in a rural area in central Sri Lanka. Each of these subjects had the fasting blood sugar estimated and the height, weight, resting blood pressure and socio-economic parameters, such as the level of education, occupation and monthly income, recorded. These data were compared with those of a similar study conducted by the main author in the same community ten years ago. The results revealed that the age-standardised prevalence of diabetes had increased from 2.5% in 1990 to 8.5% in 2000 (p = 0.008) and that this was accompanied by an increase in the monthly income, level of education and body mass indices. Since nearly 70% of all Sri Lankans live in villages, continuation of the present trend would result in a dramatic increase in the number of patients with diabetes in the future. Suitable strategies should be implemented to arrest this trend and manage a large number of patients with diabetes in the future.