ABSTRACT Background Clinical diagnosis of ankyloglossia and its therapeutic management through lingual frenotomy (LF) have increased in several countries. However, systematic reviews (SRs) and experts opinions show conflicting results on this topic. Aim To synthesize the available knowledge with a critical evaluation of SRs on LF in infants up to 1 year of age on breastfeeding‐related outcomes. Design An umbrella review was carried out. Searches were conducted (seven electronic databases, gray literature). SRs of clinical trials involving infants up to 1 year of age undergoing LF to treat maternal self‐efficacy related to breastfeeding, nipple pain, and/or weight gain were included. The articles were critically analyzed (AMSTAR 2). Results We identified 272 studies; 15 SRs were included. Confidence was classified as critically low ( n = 14; 93.3%) and moderate ( n = 1; 6.7%). Fourteen SRs had more than two critical aspects, indicating that the studies were not conducted properly. Conclusion The evidence on the efficacy of LF in infants remains inconclusive in relation to breastfeeding outcomes, especially maternal self‐efficacy related to breastfeeding and weight gain. Evidence of benefit for the treatment of breast pain is weak. Overdiagnosis of ankyloglossia may lead to overtreatment of the condition, without high‐quality evidence to support the benefits of this procedure.