INTRODUCTION: High blood pressure is a systemic disease which has major clinical and psycho-social repercussions, involves a high morbidity-mortality rate and generates high costs for the health system. Its treatment involves the use of antihypertensive drugs, which are commercialized as trademark, generic or similar drugs. PURPOSE: To verify the antihypertensive effect produced by a similar dose of different trademarks of enalapril maleate in spontaneously hypertensive rats (SHR). METHODS: Fifteen mg/kg of enalapril maleate were administered by gavage in 50 SHR rats and their blood pressure was verified through tail plethysmography every three days in a period of 16 days. RESULTS: The group treated with reference drug has shown a significant reduction on blood pressure levels when compared to the control group. Thus, treatments with enalapril maleate of generic, similar-A and similar-B brands have also shown significant reduction on animals' blood pressure. CONCLUSION: The use of generic drug and similars (A and B) drugs in the same doses and for the same period of time has not shown significant difference regarding the reference drug, which suggests that the brands tested are bioequivalent.