Despite substantial evidence of maternal and infant benefits of breastfeeding, adolescent mothers initiate breastfeeding less often and maintain breastfeeding for shorter durations when compared to their adult counterparts. A randomized controlled trial drawing on the theory of planned behavior and developmental theory was conducted to determine if an education and counseling intervention provided by a lactation consultant-peer counselor team increased breastfeeding initiation and duration up to 6 months postpartum among adolescent mothers. Study participants ( N = 289) enrolled from multiple prenatal clinic and school settings, were 15 to 18 years old, and predominately African American, single, and primiparous. The intervention, which started in the second trimester of pregnancy and extended through 4 weeks postpartum, positively influenced breastfeeding duration (p < .001) within the experimental group, but not breastfeeding initiation or exclusive breastfeeding rates. This education/support intervention was partially effective in enhancing breastfeeding outcomes. Implications for research and practice are described.