Infant and young child feeding practices were investigated in a sample survey (1132 mothers) in a rural area in northern Vietnam. Pre-lacteal feeding was almost universal. Mean duration of breast feeding was 17 months, but foods other than breast milk were introduced early. Only 50% of infants between 3 and 5 months of age were predominantly breast fed. The educational level of the mother was strongly associated with breast feeding duration, with illiterate mothers breast feeding the longest. Christian mothers breast fed for longer than non-Christians. Very few were using feeding bottles at the time of the study, although formulas and bottles have recently been appearing on the local market. The breast feeding pattern described together with the rapidly changing social and economic situation in Vietnam could mean a risk of rapid decline in breast feeding.