The article presents modern data on the structure of the lingual frenulum in newborns and factors associated with restricted tongue mobility besides the length of the mucosal part of the frenulum. The diversity of these factors dictates to limit the indications for frenectomy in newborns to cases with breastfeeding negative events evaluated and documented by a pediatrician. The assessment protocol should include weight gain but also child and mother position, duration, and comfort of the breastfeeding sessions, as well as breast condition in mother. The cases of long-term complications of frenotomy performed in newborns are described, as well as a case illustrating indications for frenotomy associated with chronic injury (Riga-Fede disease).