There have been numerous recent reports of case series of type 2 diabetes mellitus (DM) in American Indian, African-American, Hispanic, Asian-American and white children from North America. A similar phenomenon has also been described in several other countries. Prevalence and incidence estimates vary depending on the age and ethnicity of the population, but it is estimated that type 2 DM represents 8-45% of patients with DM currently diagnosed in large US pediatric centers; however, this is likely to be an underestimation and incidence is probably rising. The young patients diagnosed with type 2 DM in the USA were generally overweight, had a strong family history of type 2 DM and often had signs of insulin resistance. The majority belonged to ethnic groups at high risk for type 2 DM. More girls than boys were diagnosed. The few data on follow-up available suggest a high prevalence of microvascular and macrovascular complications among young adults who developed type 2 DM during childhood. Type 2 DM in children has recently been recognized as a potential public health problem in North America. As obesity is currently on the increase in several industrialized or industrializing countries, a similar increase in type 2 DM in children may soon emerge worldwide, and this will require preventative measures.