Lower urinary tract symptoms (LUTS) are categorized as storage, voiding, and post-micturition symptoms of the lower urinary tract. Recent clinical evidence have shown that hypertension and atherosclerosis resulting in disturbed blood flow are linked to the development of LUTS. Spontaneously hypertensive rat (SHR) is genetically hypertensive rat and shows various urinary disorder model such as detrusor overactivity/overactive bladder and benign prostatic hyperplasia (BPH) with a decrease in pelvic blood flow. Alpha1 adrenoceptor antagonists are widely used as the treatment of BPH/LUTS. Moreover, there is increasing evidence that alpha1 adrenoceptor antagonists improve the voiding symptoms as well as storage symptoms in BPH/LUTS patients. We reported that chronic daily treatment with silodosin (a selective alpha1A adrenoceptor antagonist) ameliorated the decreased bladder blood flow and urodynamic parameter in SHR. Moreover, chronic treatment with silodosin improved the prostatic morphological changes and decreased prostatic blood flow in SHR. These data suggest that silodosin might improve the LUTS via a recovery of pelvic blood flow.