Purpose: The prevalence of erectile dysfunction (ED) is higher in patients with lower urinary tract symptoms (LUTS). Phosphodiesterase 5 inhibitors (PDE5is) can improve both ED and LUTS and therefore is useful for these patients. Our aim of this study is to evaluate whether combination therapy of alpha blockers and PDE5i is more effective than alpha-blockers monotherapy for the treatment of LUTS. Materials and Methods: A systematic review and meta-analysis were undertaken to assess the difference between the combination therapy and alpha-blockers monotherapy by searching published randomized controlled trials from electronic databases PubMed, Embase, and the Cochrane Library up to April 2018. Results: A total of 13 randomized controlled studies with 1173 patients were included in our meta-analysis. Compared with alpha-blocker monotherapy, the combination therapy obtained a significantly better improvement in International Prostate Symptom Score (IPSS) (1.73, 95% confidence interval [CI]: 1.1-2.35), voiding subscore (0.99, 95% CI: 0.54-1.44), storage subscore (0.57, 95% CI: 0.03-1.1), peak flow rate (0.69 cc/s, 95% CI: 0.27-1.1), and erectile function (EF) symptom score. Meta-regression showed that baseline IPSS, baseline peak flow rate, baseline prostate volume, age, baseline EF symptom score, and dosage of PDE5is were not associated with the difference in IPSS improvement. Conclusion: A combination of alpha blockers and PDE5is has better therapeutic effects than alpha-blocker monotherapy on LUTS related to benign prostate hyperplasia.