Background: Tongue-tie (ankylglossia) occurs when there is an anterior attachment near the tip of the tongue resulting in restricted tongue movement. It is reported to be a cause of poor breastfeeding in infants and nipple pain in breastfeeding mothers. Objectives: The objectives of the study were to determine whether frenotomy is safe and effective in improving ability to feed orally among infants. Intervention/methods: Frenotomy may correct the restriction of tongue movement and allow improved breast feeding and reduced maternal nipple pain. Randomised, quasi-randomised cluster-randomised controlled trials that compared frenotomy verses no frenotomy or frenotomy verses sham procedure were included in the review. Participants were infants with tongue-tie experiencing feeding problems, or whose breast feeding mothers were experiencing nipple pain. Results: Five studies (N = 302) met the inclusion criteria. Pooled analysis of two studies showed no change following frenotomy (mean difference (MD) −0.1, 95% confidence interval (CI) −0.6 to 0.5 units on a 10-point feeding scale). A third study showed objective improvement on a 12-point feeding scale (MD 3.5, 95% CI 3.1 to 4.0 units of a 12-point feeding scale). Pooled analysis of three studies (n = 212) showed a reduction in maternal pain scores following frenotomy (MD −0.7, 95% CI −1.4 to −0.1 units on a 10-point pain scale). These studies had serious methodological shortcomings. Conclusion: Investigators did not find a consistent positive effect on infant breastfeeding following frenotomy. A short-term reduction in breast pain was found among breastfeeding mothers. Small trial numbers and methodological issues meant no definitive benefit for frenotomy in infants with tongue-tie could be proved.