Neonatal abstinence syndrome is seen commonly in infants born to women on methadone maintenance. Many of these infants are breast-fed but few data are available on the distribution of methadone in breast milk, particularly for women receiving doses greater than 60 mg daily. We report two infants who appeared to develop neonatal abstinence syndrome, after abrupt discontinuation of breast-feeding by women receiving 70 mg and 130 mg of methadone. Women on methadone maintenance on high doses should be counselled to wean breast-feeding gradually.