INTRODUCTION: Statin therapy has proved effective in reducing cardiovascular morbidity and mortality. However, the cost of a defined daily dose (DDD) differs from a statin to another, being generally atorvastatin and simvastatin the best choice under the criteria of cost effectiveness. OBJECTIVES: To assess the consequences in terms of outpatient pharmaceutical expenditure and DDD prescribed, that accounted due to the introduction of “prescription algorithms” into the electronic prescribing tool for physicians. Check whether the prescription of statins has been moved towards cost effective alternatives. METHODS: Cross-sectional study during 2012, 2013 and 2014. Two health regions of Spain (Comunitat Valenciana with 4.949.219 inhabitants and Extremadurawith 1.093.587. Total population: 6,042,806) where compared. In order to make it comparable, DDDs where measured as numbers of DDDs/1000 inhabitants/day (DHDs). RESULTS: Atorvastatin and simvastatin are the most prescribed statins in both regions. However in Extremadura, the proportion of DHD of these two chemical substances over the total amount of statins has decreased from 70.13% in 2012 to 68.00% in 2014. By contrast, in Comunitat Valenciana the proportion has increased from 73.45% in 2012 to 82.40% in 2014. In both regions the number of DHD of statins increases (in Extremadura from 106.75 DHD in 2012 to 120.14 DHD in 2014; in Comunitat Valenciana from 98.08 DHD in 2012 to 104.15 DHD in 2014). However, in Comunitat Valenciana the increase in consumption has not resulted in increased drug spending but in a drop of 7.41%. By contrast, Extremadura’s pharmaceutical expenditure of statins has increased a 17.62%. CONCLUSIONS: In the region that did not introduced the algorithm for statins into the electronic prescribing tool, less cost effective statins are gaining market share. In the region which introduced the prescription algorithm, although statin use increases, its pharmaceutical expenditure decreases, resulting in savings that can be spent elsewhere medication.