In the last decade, an increased number of new cases of type 2 diabetes mellitus (T2DM) among patients who use statins have been reported. The aim of the present review is to compile the most relevant information about the risk of T2DM associated with the use and dose of different statins, especially based on meta-analysis considering different studies worldwide. To explain this relationship, several studies have reported the effect of statins on insulin resistance in dyslipidemic non-diabetic patients, reporting different findings according to the types of statins. In addition, some reports -based on culture of β pancreatic cells- have evaluated the effect of these drugs in certain cellular events that are essential for insulin secretion. Clearly, further studies in humans are needed -applying more robust tests than those used up to date- in order to define more precisely the potential mechanisms explaining the higher incidence of T2DM among statin users.