This study examined the degree to which first-time mothers' perceptions of their marital relationships, various support systems, and adjustment to pregnancy and motherhood were associated with success at initiating and maintaining lactation during the first year postpartum. Additionally, the incidence and duration of breastfeeding, feeding problems encountered, as well as the sources and quality of feeding-related help received by these mothers were examined. Mothers in this study showed a pattern of breastfeeding incidence and duration similar to that established statewide and nationwide. The most prevalent problem encountered by these mothers during the first postpartum month was a concern of inadequate milk supply. The type of feeding-related support received varied by source: husbands and (grand)mothers provided the greatest degree of emotional and instrumental support, while doctors and nurses provided more information, which was also associated with success at establishing lactation. Mothers who were themselves breastfed as infants nursed their infants more at one month than those who were bottle-fed. Long-term breastfeeding mothers were those who had adjusted most optimally to pregnancy and motherhood, were most likely to characterize their marriages as satisfying and loving during the prenatal period and throughout the first postpartum year, and were most satisfied with the nature and extent of support received from husbands.