The age of onset of Type 2 diabetes mellitus (T2DM) is falling and this condition is not uncommon among those aged less than 30 years, including children and adolescents. Early-onset T2DM has been reported in countries with different ethnic and cultural backgrounds. This phenomenon heralds an important public health issue reflecting the effects of a sedentary lifestyle as part of the globalization and industrialization that is affecting all societies. The pathophysiology of early-onset T2DM is similar to the later onset cohort characterized by β-cell failure and obesity-induced insulin resistance but the rate of decline in β-cell function appears to be more rapid. Recent evidence suggests that early-onset T2DM is a more aggressive disease phenotype than the later onset cohort and develops cardiovascular complications, reflected by more adverse cardiovascular risk profile and higher relative risk of myocardial infarction and cardiovascular death. As there is a paucity of clinical trial evidence in this population, clinical judgment is required to initiate treatments to prevent cardiovascular complications guided by assessment of global cardiovascular risk. Future research strategies in this cohort include population-based studies in at-risk populations, exploration of its natural history, development of complications and outcome studies pertaining to the treatment of cardiovascular risk factors.