ABSTRACTThis study was done in order to obtain information about current breastfeeding behavior among resident and migrant lactating mothers in Hanoi Vietnam for the general purpose of breastfeeding promotion in Vietnam. The research hypothesis is that there is a different breastfeeding behavior of resident and migrant lactating mothers. A cross-sectional study was carried out between December 1994 and March 1995. The subjects consisting of 80 lactating mothers with 9 months old baby are divided into 2 groups. Those mothers have been living for at least 15 years in Hanoi (resident mothers) and the other mothers for between 5 months to 3 years (migrant mothers). Information of breastfeeding behavior and the socioeconomic status of mothers were obtained by using open-ended questionnaire. A second questionnaire was applied to 30 health professionals in maternity clinics where the mothers delivered. One hundred percent of mothers breastfed their child, 95% of the resident and 85% of the migrant mothers were still breastfeeding at the time of the study. Almost all of the residents (95%) and 87.5% of the migrants had positive attitude towards colostrum. About 42.5% of the resident mothers and 35% of the migrant ones started breastfeeding within 6 hours after birth. The rooming-in rate was 67.5% of the resident mothers and 52.5% of the migrant ones. The rate of early initiation of breastfeeding was significantly higher in the mothers group who had rooming-in than the others. The exclusive breastfeeding rate within the first 4 months of age was 35% of the residents and 30% of the migrants. All health professionals (100%) had positive attitude towards colostrum and breastfeeding. About 86.7% of doctors and 80% of midwives knew that 'mother' should start breastfeeding within the first 30 minutes after birth. Around 86.7% of doctors and 100% of midwives said that there was no need to give other liquid before starting breastfeeding. But their practices were not according to their knowledge: They gave wrong advises to the resident mothers (8.7%)., about 38.4% of babies from the resident mothers and 60.9% of babies from migrant ones were prelacteal fed by health professionals. Additional information on breastfeeding and child feeding were still expected by mothers especially by the migrant ones (71.4%). The results of the study suggest education on breastfeeding and proper feeding practices, especial early initiation, prolonged exclusive breastfeeding, and rooming-in.