BACKGROUND: Despite high levels of breastfeeding initiation in Australia, only 46 percent of women are still breastfeeding (exclusively or partially) 6 months later, with marked differences between social groups. This study aimed to determine the influence of mid-pregnancy breastfeeding education on the proportions of women breastfeeding at hospital discharge, and on the duration of breastfeeding. METHODS: A randomized controlled trial to compare two strategies for increasing the initiation and duration of breastfeeding was conducted, in which 981 primiparas who attended a public, tertiary women's hospital in Melbourne, Australia, were randomized to one of two interventions or to standard care (327 in each group). The interventions were a 1.5-hour class on practical aspects of breastfeeding using a previously tested tool (Practical Skills), and two 1-hour classes exploring family and community attitudes toward, and experiences of, breastfeeding (Attitudes). Both interventions took place in interactive small groups when women were in mid-pregnancy. Breastfeeding initiation was ascertained by interview 2 to 4 days after birth, and breastfeeding duration was assessed by telephone interview 6 months after birth. RESULTS: Neither intervention increased breastfeeding initiation or duration compared with standard care. Rates at initiation were 97 percent (296/306) for the Practical Skills intervention, 95 percent (291/308) for the Attitudes intervention, and 96 percent (297/310) for standard care. Rates at 6 months were, respectively, 55 percent (162/297), 50 percent (146/293), and 54 percent (162/299). CONCLUSIONS: In settings where breastfeeding initiation is already high, neither study intervention could be recommended as an effective strategy to increase breastfeeding initiation or duration.