Background: Diabetes mellitus has reached epidemic proportions worldwide. South Asians are known to have an increased predisposition for diabetes which has become an important health concern in the region. We discuss the prevalence of pre-diabetes and diabetes in South Asia and explore the differential risk factors reported. Methods: Prevalence data were obtained by searching the Medline® database with; prediabetes and diabetes mellitus (MeSH major topic) and Epidemology/EP (MeSH subheading). Search limits were articles in English, between 01/01/198031/12/2011, on human adults (≥19 years). The conjunction of the above results was narrowed down with country names. Results: The most recent reported prevalence of pre-diabetes:diabetes in regional countries were; Bangladesh4.7%:8.5% (20042005;Rural), India4.6%:12.5% (2007;Rural); Maldives3.0%:3.7% (2004;National), Nepal19.5%:9.5% (2007;Urban), Pakistan3.0%:7.2% (2002;Rural), Sri Lanka11.5%:10.3% (20052006;National). Urban populations demonstrated a higher prevalence of diabetes. An increasing trend in prevalence of diabetes was observed in urban/rural India and rural Sri Lanka. The diabetes epidemicity index decreased with the increasing prevalence of diabetes in respective countries. A high epidemicity index was seen in Sri Lanka (2005/200652.8%), while for other countries, the epidemicity index was comparatively low (rural India 200726.9%; urban India 2002/200531.3%, and urban Bangladesh33.1%). Family history, urban residency, age, higher BMI, sedentary lifestyle, hypertension and waist-hip ratio were associated with an increased risks of diabetes. Conclusion: A significant epidemic of diabetes is present in the South Asian region with a rapid increase in prevalence over the last two decades. Hence there is a need for urgent preventive and curative strategies.