To evaluate factors associated with initiation and duration of breastfeeding in Italy, 1601 (73%) respondents among 2192 randomly selected mothers were interviewed within 1 mo of delivery. Mothers who started breastfeeding (85%) were followed-up for 12 mo. A compliance rate of 100% was obtained. At multiple logistic regression analysis, mother having been breastfed herself (p < 0.01), nursing guidance in the maternity ward (p = 0.01) and higher social class (p = 0.03) were positively associated with initiation of breastfeeding. We found that 42%, 19%, 10% and 4% mothers were still breastfeeding at 3, 6, 9 and 12 mo after delivery, respectively. Cox multiple regression analysis showed a negative association between duration of breastfeeding and pacifier use (p < 0.01), and a positive association with a higher level of maternal education (p = 0.04). Formula supplementation in the maternity ward (given to 30% of infants) was associated with a shorter duration of exclusive breastfeeding (p = 0.03). Mothers need support with breastfeeding, particularly those from lower social backgrounds and with lower levels of education. Early use of the pacifier should be discouraged.