Introduction/Framework Diabetes mellitus is a chronic disease resulting from deficient secretion and/or peripheral insulin action, causing hyperglycemia, with multiple organ damage. The worldwide Diabetes mellitus incidence has increased in recent decades, with an estimated worldwide prevalence close to 415 million adults. In this context, a lot of workers with this disease will be accessed through medical examination to evaluate fitness for work, so it is essential that the Occupational Physician remains updated about the clinic and the available pharmacological options to deliberate on aptitude, restrictions and recommendations for a specific job/task. Methodology It’s a narrative review of the available evidence from the PubMed database, complemented by the national and international guidelines and the Portuguese law. Contents/Discussion DM complications can affect the ability to work and should motivate periodic evaluation by the Occupational Physician. Some chronic complications are evident in their likelihood of disability, such as retinopathy or neuro-ischemic disease, which often motivate work restrictions. On the other hand, acute complications, although often mild and self-limited, can put the worker at serious risk of an occupational accident. Severe hypoglycemia, with neuroglycopenic symptoms, is the most obvious example. The pharmacotherapy itself can cause hypoglycemic episodes or other symptoms that put the safety of the worker and even others at risk. Workers with DM who work at heights, who handle dangerous equipment or who drive professionally, must be carefully evaluated by the Occupational Physician. Although most will not have work restrictions, it may be necessary to adapt the workplace or limit certain tasks to achieve adequate glycemic control, a determining factor for preventing complications. Recommendations for workers with diabetes include breaks for glycaemic control, food ingestion and/or therapeutic administration, appropriate choice of protective equipment and, eventually, restriction of night shifts or some tasks with high metabolic expenditure. Those recommendations depend on the awareness of hypoglycaemea, the pharmacotherapy used to control diabetes and the complications of the disease. Conclusion Occupational Physician needs to be updated about Diabetes Mellitus management tools, pharmacotherapy, with particular attention to eventual side effects, to control and prevent professional risks arising from poor control. Keywords: Diabetes mellitus; Antihyperglycemic Pharmacotherapy; Fitness for Work Assessment; Occupational Health.