Tamsulosin is a therapeutic drug of alpha-adrenergic antagonists. Previous randomized controlled trials and retrospective analyses have proved the efficacy of tamsulosin on many urinary system diseases. However, there is still a conflict about whether tamsulosin could prevent postoperative urinary retention (POUR). This meta-analysis aims to probe into the efficacy of tamsulosin for preventing POUR versus placebo. We searched MEDLINE, EMBASE, and Cochrane Library from December 31, 1999 to April 30, 2022, for randomized controlled trials (RCTs). Studies that were not RCTs or without negative controls were excluded. Cochrane Collaboration harmonized criteria were used to assess the risk of bias in included studies. Revman (version 5.3) software was invited to synthesize the results. We performed subgroup analyses to explore the factors that could influence tamsulosin's efficacy in POUR prevention. Our meta-analysis pooled 13 RCTs with 2163 patients. We concluded that tamsulosin brought about a significant reduction in the risk of POUR versus placebo (13.54% vs 20.88% for tamsulosin vs placebo, RR = 0.63, 95% CI 0.47 to 0.84, P = 0.002). Tamsulosin could significantly reduce the risk of POUR in abdominal (11.52% vs 20.25% for tamsulosin vs placebo, RR = 0.52, 95% CI 0.31 to 0.88, P = 0.02) and female pelvic surgery (15.57% vs 31.50% for tamsulosin vs placebo, RR = 0.51, 95% CI 0.31 to 0.82, P = 0.006) but not in spinal surgery (13.45% vs 12.75% for tamsulosin vs placebo, RR = 1.07, 95% CI 0.72 to 1.60, P = 0.73) and lower limb surgery (21.43% vs 33.33% for tamsulosin vs placebo, RR = 0.64, 95% CI 0.35 to 1.14, P = 0.13). The preventive effect of postoperative (17.70% vs 33.93% for tamsulosin vs placebo, RR = 0.53, 95% CI 0.33 to 0.85, P = 0.008) and postoperative with preoperative tamsulosin (13.96% vs 23.44% for tamsulosin vs placebo, RR = 0.64, 95% CI 0.43 to 0.93, P = 0.02) on POUR were significantly better than preoperative management (11.95% vs 14.63% for tamsulosin vs placebo, RR = 0.62, 95% CI 0.23 to 1.65, P = 0.34). Postoperative catheter placement appears to have a negative impact on the POUR-preventive effect of tamsulosin. (9.37% vs 16.46% for tamsulosin vs placebo, RR = 0.51, 95% CI 0.31 to 0.83, P = 0.007) Tamsulosin showed significantly effect on POUR prevention in patients during spinal (15.07% vs 26.51% for tamsulosin vs placebo, RR = 0.52, 95% CI 0.31 to 0.90, P = 0.02) and epidural anesthesia (12.50% vs 29.79% for tamsulosin vs placebo, RR = 0.42, 95% CI 0.18 to 1.00, P = 0.05) but not in general anesthesia (12.40% vs 18.52% for tamsulosin vs placebo, RR = 0.68, 95% CI 0.45 to 1.03, P = 0.07). Tamsulosin shows better outcomes for preventing POUR than placebo. Besides, tamsulosin showed a different effect on POUR prevention in the various surgical sites, anesthesia, medication management, and catheter use. However, our conclusions still have some limitations due to the lack of evidence.