BACKGROUND: New minimal invasive surgeries have been suggested as alternative options to transurethral resection of the prostate (TURP) for the management of lower urinary tract symptoms (LUTS) in men with benign prostatic hyperplasia (BPH). Convective radiofrequency water vapour thermal therapy is a new technology that uses targeted, controlled water vapour energy (steam) to create necrotic tissue in the prostate. OBJECTIVES: To assess the effects of convective radiofrequency water vapour thermal therapy for the treatment of lower urinary tract symptoms in men with benign prostatic hyperplasia. SEARCH METHODS: We performed a comprehensive search of multiple databases (the Cochrane Library, MEDLINE, Embase, Latin American and the Caribbean Health Sciences Literature, Scopus, Web of Science), trials registries, other sources of grey literature, and conference proceedings published up to 18 February 2020, with no restriction on the language or status of publication. SELECTION CRITERIA: We included parallel-group randomised controlled trials (RCTs), cluster-RCTs, and non-randomised observational prospective studies with concurrent comparison groups, in which men with BPH underwent convective radiofrequency water vapour thermal therapy, another active therapy, or a sham procedure. DATA COLLECTION AND ANALYSIS: Two review authors independently screened the literature, extracted data, and assessed risk of bias. We had planned to perform statistical analyses using a random-effects model, and interpret them according to the Cochrane Handbook for Systematic Reviews of Interventions. We rated the certainty of the evidence according to the GRADE approach. MAIN RESULTS: We included a single, industry-sponsored RCT, with 197 randomised men, that compared convective radiofrequency water vapour thermal therapy to a sham procedure. The mean age 62.9 years, the International Prostate Symptom Score (IPSS) was 21.97, and the mean prostate volume was 45.4 mL. We only found short-term data, measured up to three months. Primary outcomes Convective radiofrequency water vapour thermal therapy may improve urologic symptom scores more than a sham procedure, measured on a IPSS scale (0 to 35; higher score represents worse urological symptoms) by a mean difference (MD) of -6.9 (95% confidence interval (CI) -9.06 to -4.74; 195 men; low-certainty evidence), and likely improves quality of life (QoL), measured on a IPSS-QoL scale (0 to 6; higher score represents worse QoL), by a MD of -1.2 (95% CI -1.66 to -0.74; 195 men; moderate-certainty evidence). We are very uncertain about the effects of convective radiofrequency water vapour thermal therapy on major adverse events (risk ratio (RR) 6.79, 95% CI 0.39 to 117.00; 197 men; very low-certainty evidence) assessed by the Clavien-Dindo classification system of III, IV, and V complications. Secondary outcomes We are very uncertain about the effects of convective radiofrequency water vapour thermal therapy on retreatment (RR 1.36, 95% CI 0.06 to 32.86; 197 men; very low-certainty evidence). Convective radiofrequency water vapour thermal therapy may have little to no effect on erectile function (MD 0.4, 95% CI -1.91 to 2.71; 130 men; low-certainty evidence) and ejaculatory function (MD 0.5, 95% CI -0.83 to 1.83; 130 men; low-certainty evidence). Convective radiofrequency water vapour thermal therapy may increase minor adverse events assessed by the Clavien-Dindo classification system of Grade I and II complications (RR 1.89, 95% CI 1.15 to 3.11; 197 men; low-certainty evidence). This would correspond to 434 minor adverse events per 1000 men (95% CI 264 more to 714 more). We are very uncertain about the effects of convective radiofrequency water vapour thermal therapy on acute urinary retention (RR 4.98, 95% CI 0.28 to 86.63; 197 men; very low-certainty evidence). It likely greatly increases the rate of men requiring indwelling urinary catheters (RR 35.58, 95% CI 15.37 to 82.36; 197 men; moderate-certainty evidence). We were unable to perform any of the predefined secondary analyses. We found no evidence for other comparisons, such as convective radiofrequency water vapour thermal therapy versus TURP or other minimal invasive procedures. AUTHORS' CONCLUSIONS: Compared to a sham procedure, urologic symptom scores and quality of life appear to improve with convective radiofrequency water vapour thermal therapy, but we are very uncertain about major adverse events. The certainty of evidence ranged from moderate to very low, with study limitations and imprecision being the most common reasons for rating down. These findings are based on a single industry-sponsored study, with three-month short-term follow-up. We did not find any studies comparing convective radiofrequency water vapour thermal therapy to any other active treatment form, such as TURP.