This study assessed indications for and safety and outcome of simple division of tongue tie without an anesthetic. There were 215 infants younger than 3 months (mean 0-19 days) who had major problems breastfeeding, despite professional support. Symptoms, tongue tie details, safety of division, and complications were recorded. Feeding was assessed by the mothers immediately, at 24 hours, and 3 months after division. Prior to division, 88% had difficulty latching, 77% of mothers experienced nipple trauma, and 72% had a continuous feeding cycle. During division, 18% slept throughout; 60% cried more after division (mean 0-15 seconds). There were no significant complications. Within 24 hours, 80% were feeding better. Overall, 64% breastfed for at least 3 months (UK national average is 30%). Initial assessment, diagnosis, and help, followed by division and subsequent support by a qualified lactation consultant, might ensure that even more mothers and infants benefit from breastfeeding.