Objetives. To identify prevalence and incidence studies of type 2 diabetes mellitus in the general adult population in Peru. Materials and Methods. Observational studies involving randomly selected individuals from the general population were evaluated. The definition of diabetes had to include at least one laboratory parameter (e.g. baseline glucose). LILACS, SciELO, Scopus, Medline, Embasem and Global Health were reviewed without restriction. Risk of bias was assessed using the Newcastle-Ottawa scale. Results. The search identified 909 results; additionally, an article from another source was added. After evaluating the results, 20 articles representing nine studies were selected (n=16 585). One of the studies was national in scope and another semi-national (ENINBSC, 2004-05 and PERUDIAB, 2010-12). The first study reported a prevalence of 5.1% in subjects ≥35 years, while the second reported 7.0% in subjects ≥25 years. Other studies focused on populations in one or more cities in the country, or on selected population groups, such as the PERU MIGRANT study (2007-08) which reported the prevalence of diabetes in subjects in rural areas (0.8%), in rural-urban migrants (2.8%), and in urban areas (6.3%). Three studies followed up prospectively, one of them being PERUDIAB: a cumulative incidence of 19.5 new cases per 1,000 people per year. The risk of bias was low in all studies. Conclusions. Population studies indicate that the prevalence of diabetes has increased and that there are approximately two new cases per 100 people per year. Evidence is still scarce in the jungle and in rural populations.