We aimed to summarize in a systematic review the current evidence on the effectiveness of electrical stimulation in the treatment of erectile dysfunction. Following the PRISMA guidelines, we performed a literature search for randomized controlled trials using Medline, CINAHL, Embase, and Web of Science, and searched unpublished studies and trial registrations. We used Cochrane's risk-of-bias assessment tool and GRADE system to assess the certainty of evidence. From 3 586 potentially relevant records, we included three trials. Overall, 82 men with erectile dysfunction (20-65 years old), assessed using the IIEF-5 questionnaire, were randomized. Transcutaneous electrical stimulation was compared to placebo (Mean difference-MD:4.60, 95% Confidence interval-CI 0.28-8.92, n = 22), aerobic exercise (MD:6.50, 95%CI 5.10-7.90, n = 30), and used in association with pelvic floor muscle training with biofeedback and compared to the same procedure without electrical stimulation (MD:4.80, 95% CI 1.29-8.31, n = 30). We were unable to combine studies for meta-analysis due to clinical heterogeneity. This review was limited by the quality of existing evidence. The certainty of the evidence was very low due to risk of bias and small sample sizes. There is inconclusive evidence of the effectiveness of electrical stimulation in the treatment of erectile dysfunction.