Background The primary objectives of the treatment for the lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH) are to produce rapid, sustained, and safe improvements in the symptoms that affect the quality of life in the majority of men over 50. In this study, we evaluated the efficacy and safety of the combined therapy with terazosin (α1-adrenergic receptor antagonist) and tolterodine (anticholinergic agent) for LUTS associated with BPH.Methods This combination study included 69 patients diagnosed with LUTS associated with BPH based on the Intational Prostate Symptom Scores (IPSS), urinary flow rate, prostate volume, urinary residual, and their serum prostate-specific antigen levels. Initially, 191 patients were treated with terazosin 2 mg once daily for one week. Those patients with continued LUTS after the initial treatment were allocated randomly into two groups: terazosin group (n=36)in which patients were treated with terazosin 2 mg once daily for six weeks, and combination group (n=33) in which patients were treated with both terazosin 2 mg once daily and tolterodine 2 mg twice daily for 6 weeks.Results The IPSS were significantly improved in both groups after treatment, and the reduction of IPSS in the combination group was significantly greater than that in the terazosin group (P＜0.01). A decrease in urgency, frequency and nocturia were the main contributory factors causing the reduction of IPSS in the combination group. The differences about the peak urinary flow rate and the residual urine from the baseline values were noted in both groups after treatment,but were not significant between the two groups. The incidence of adverse effects in the combination group was higher than that in the terazosin group. As expected the most common adverse effect was mouth dryness which was associated with anticholinergic drugs such as tolterodine.Conclusions Patients with LUTS associated BPH appear the improved IPSS after combined therapy with terazosin and tolterodine. This study, although short term and limited numbers of patients, provides evidence that the combined therapy with terazosin plus tolterodine is a good approach for meeting the objectives of rapid, sustained, and safe improvements in the LUTS associated with BPH. And the profile of patients in this study might be used as the indication of such combined therapy for LUTS associated with BPH without urodynamic evaluation.