OBJECTIVE: To evaluate the effectiveness of interventions aimed at the prevention of risk factors and incidence of type 2 diabetes in the workers population. METHODS: Systematic review of interventions aimed at adult workers at risk of type 2 diabetes published in Medline, Embase, Web of Science, Central Cochrane Registry of Controlled Trials, and Lilacs. Randomized trials, quasi-experimental research and cohort studies were selected; in English, Spanish and Portuguese; published from 2000 to 2017. Intervention effectiveness was evaluated concerning the incidence of type 2 diabetes and a significant reduction in body weight, or another anthropometric or metabolic parameter. RESULTS: 3,024 articles were generated, of which 2,825 that did not answer the research question were eliminated, as well as 130 that did not evaluate original interventions, 57 carried out outside the workplace and two reviews; so that 10 selected items remained. Interventions based on structured programs previously evaluated and integrated into the workplace had a favorable impact on the reduction of body weight and other risk factors. CONCLUSIONS: The effectiveness of lifestyle interventions for the prevention of type 2 diabetes should be based on structured programs with proven effectiveness and adapted to the workplace, with employer participation in the provision of schedules and work environments.