- Women taking methadone or buprenorphine are encouraged to breastfeed if stable without polysubstance use.We aimed to determine the difference between stated intention to breastfeed prenatally in women taking methadone or buprenorphine compared with breastfeeding at discharge and 2 months postpartum. Secondary outcomes were determining whether breastfeeding was more common in women taking buprenorphine, in women without hepatitis C infection, and in women without a history of heroin use, and whether breastfeeding reduced the need for pharmacological treatment of neonatal opioid withdrawal syndrome.This was a retrospective cohort study of 228 women enrolled in a perinatal substance abuse treatment program. Electronic medical records were reviewed to abstract data on mother-infant dyads. Chi-square tests were used to analyze our outcomes.Women taking buprenorphine had a higher prevalence of breastfeeding compared with women taking methadone (83% [ n = 100] vs. 71% [ n = 76]; χ2 = 4.35, p = .03), despite no difference in their prenatal intention to breastfeed (87% vs. 81%; χ2 = 1.28, p = .25). Only 31% ( n = 38) of women taking buprenorphine and 19.6% ( n = 21) of women taking methadone exclusively breastfed at discharge (χ2 = 5.43, p = .06). Exclusively breastfed infants required less pharmacological treatment for neonatal opioid withdrawal syndrome compared with formula-fed infants (15.8% [ n = 21] vs. 47.4% [ n = 38]; χ2 = 19.72, p < .05).Despite most women reporting a high prenatal intention to breastfeed, exclusive breastfeeding at hospital discharge postpartum was low. Breastfeeding was associated with a decreased likelihood of pharmacological treatment for neonatal opioid withdrawal syndrome.