OBJECTIVES: To calculate and compare costs of primary treatment of hypertension with candesartan / hydrochlorothiazide (HCT) or losartan / HCT in the Mexican Social Security Institute (IMSS). METHODS: An adaptation from Kjeldsen observational study of 14,100 patients diagnosed with hypertension and the costs’ sub analysis of Henriksson was made to have an approximation of incurred costs by IMSS when using candesartan / HCT or losartan / HCT in the primary hypertension treatment and its impact in reducing related cardiovascular events. First assumption for adaptation was to use only costs of combined therapies with HCT since monotherapies are not included in the IMSS formulary. Hospitalizations, laboratory tests and physician visits resource consumption reported by Kjeldsen were multiplied by IMSS 2010 unit costs. An average of 3.35 years follow-up was used. IMSS population with hypertension was estimated using the national prevalence of 30.8% (20 years and older) reported by the National Health Survey of 2006, the proportion (70%) of the Mexican population over 20 years old reported by the National Population Council and the number of total IMSS affiliates. A 5% discount rate was applied to costs. Results are presented in US dollars (exchange rate 13 MXN/dollar). RESULTS: Primary hypertension annual treatment cost per patient including related cardiovascular events was $556.56 for patients treated with candesartan / HCT and $718.42 with losartan/HCT treatment. Theoretical savings yield by candesartan / HCT are $161.86 per patient. Calculated hypertension patients affiliated to the IMSS was 10 million. Average annual savings given this population are $1.707 million for the institution with 1.8 million bed days, 4.4 million physician visits and 5.3 million laboratory tests avoided. CONCLUSIONS: This analysis showed that the reduction of cardiovascular events with the use of candesartan / HCT for treating primary hypertension could save $1.707 million to the IMSS.