OBJECTIVES: The aim of this paper is to analyze pharmaceutical expenditure in Alzheimer patients from a Europe southeastern region (Valencian Region (Spain)), by using the clustering patients system Clinical Risk Group (CRGs). We focused on obtaining more information about Alzheimer patients, stablishing a more accurate prediction of their resources consumption and individuating patterns of pharmaceutical consumption. METHODS: A cross-sectional study of the inhabitants of Valencian region with a population of 5,000,000 was carried out, using data extracted from Electronic Health Records for 2013. A sample of 24641 Alzheimer individuals were identified. RESULTS: From our sample 29.4% men and 70.6% women were found. The annual average cost per Alzheimer patient is € 1709.051. By gender, women average cost is 1718,66 € while men average consumption is 1685,97 €. Age is the variable which most affect pharmaceutical cost variability, while severity levels are not capable to explain cost variability. CONCLUSIONS: Valuable information about pharmaceutical cost of Alzheimer patients was found. In contradiction to other diseases, for the Alzheimer case, levels of severity does not provide a clear explanation of pharmaceutical cost variability.