In this study, we evaluated the short-term effect of a cocoa polyphenol extract (CPE), in spontaneously hypertensive rats (SHR). Male 17-22-week-old SHR were administered by intragastric gavage water, 50 mg kg(-1) Captopril or CPE at different doses (13, 26, 80 and 160 mg kg(-1)). The systolic blood pressure (SBP) and diastolic blood pressure (DBP) were recorded by the tail cuff method before the administration and also 2, 4, 6, 8, 24, 48 and 72 h post-administration. Highly significant decreases in the SBP and in the DBP were observed when captopril or CPE was administered to SHR. The cocoa extract produced a dose dependent effect in the SBP of the SHR up to the dose of 80 mg kg(-1). Nevertheless this dose of CPE did not decrease the arterial blood pressure in the normotensive Wistar Kyoto rats. The decrease in the SBP caused by 80 mg kg(-1) of CPE in the SHR (-39.1 ± 3.7 mm Hg) was maximum 6 h post-administration, and the initial values of SBP were recovered 72 h post-administration of this extract. Paradoxically, 160 mg kg(-1) of the cocoa extract caused a decreased antihypertensive effect than lower doses of CPE. In addition, the decrease in DBP was always more accentuated when the dose of CPE administered was lower. Our results suggest that CPE may be used as a functional food ingredient with beneficial effects for controlling arterial blood pressure.