To evaluate the early efficacy of the alpha(1A)-adrenoceptor selective drug, silodosin, for the treatment of lower urinary tract symptoms suggestive of benign prostatic hyperplasia. A total of 68 patients with an International Prostate Symptom Score (IPSS) of >==8 and a Quality of Life (QOL) index of >==2 were included. Changes in the IPSS and QOL index were evaluated before and after 1, 2, 3, 4, 5, 6, 7, 14, and 28 days of twice daily oral administration of 4 mg silodosin. Next, changes in IPSS subscores as well as voiding, storage, and post micturition symptoms were assessed. Changes in total IPSS based on symptom severity were also determined. Total IPSS and QOL index improved significantly from 19.38 +/- 7.46, 4.68 +/- 1.07 at baseline to 15.81 +/- 7.40, 4.22 +/- 1.30 at day 1. The subscores of voiding, storage, and post micturition symptoms were significantly decreased from 8.93 +/- 3.95, 7.97 +/- 3.88, and 2.49 +/- 1.70 at baseline to 7.28 +/- 4.09, 6.52 +/- 3.47, and 2.02 +/- 1.56 at day 1, respectively. This trend continued throughout the study. Regardless of severity, total IPSS were significantly decreased at day 1 and maintained throughout the study. Silodosin may be considered a promising treatment for benign prostatic hyperplasia/lower urinary tract symptom patients.