Motivation: Microvascular rarefaction is an aggravating factor of hypertensive end-organ damage. However, the microcirculatory effects of statins in hypertension remains unknown. Thus, this study was designed to investigate the acute effects of simvastatin and lovastatin on cerebral and muscular microcirculation in Spontaneously Hypertensive Rats (SHR). Methods: Male normotensive Wistar rats (WKY) and SHR were divided into 4 groups of 6 animals each: WKY and SHR-CTL treated with 0.9% saline solution, and SHR+SIM and SHR+LOVA treated with simvastatin (SIM) and lovastatin (LOVA) 30 mg/kg/day during 3 days orally by gavage. Systolic Blood Pressure (SBP) was measured by a computerized tail-cuff plethysmography system. We investigated brain and skeletal muscle (SM; gracilis muscle) Functional Capillary Density (FCD) of pentobarbital-anesthetized rats (75 mg/kg) using intravital fluorescence videomicroscopy. Values are means ± S.E.M., compared by Two-tailed unpaired t test. All surgical procedures and protocols were approved in accordance with the internationally accepted principles for the Care and Use of Laboratory Animals (license # L-48/12). Results: SIM administration reduced SBP in SHR (SHR-CTL 203±3 vs. SHR+SIM 172±6 mmHg; p< 0.001; in contrast LOVA treatment was not able to reduce SBP (SHR+LOVA 192±3 mmHg). SHR showed a significantly lower FCD in the gracilis muscle compared to WKY (SHR-CTL 210±17 vs. WKY 338±16 capillaries/mm2 ; p<0.01). SIM (SHR+SIM 447±20 capillaries/mm2) and LOVA (SHR+LOVA 418±22 capillaries/mm2) treatment reverted functional capillary rarefaction in the SM of SHR (SHR-CTL 210±17 capillaries/mm2; p<0.001). Cerebral FCD was reduced in SHR compared with WKY (SHR-CTL 337±61 vs. WKY 421±35 capillaries/mm2, p<0.05). The administration of SIM (SHR+SIM 530±31 capillaries/ mm2) and LOVA (SHR+LOVA 471±37 capillaries/mm2) during 3 days was capable to increase cerebral FCD in SHR (SHR-CTL 337±61 capillaries/mm2; p< 0.05). Leukocyte rolling was significantly greater in SHR when compared with WKY (SHR-CTL 6.2±0.7 vs. WKY 2.7±0.5 cells/min; p<0.05), and 3 day treatment with SIM (SHR+SIM 2.8±0.6 cells/min; p< 0.01) and LOVA (SHR+LOVA 1.8±0.5 cells/min; p< 0.001) reduced leukocyte rolling when compared with SHR (SHR-CTL 6.2±0.7 cells/min). Conclusions: Acute treatment with simvastatin and lovastatin significantly reduced brain postcapillary venules leukocyte rolling and reversed microvascular rarefaction in SHR. In addition to cholesterol-lowering effects, pleiotropic effects of statins could turn out to be a new therapeutic approach for improving microcirculatory function in hypertensive patients. However, it is necessary to further investigate the mechanisms and pathways which may additionally play important roles in statin-mediated cardiovascular protection in hypertension.