A one-year intervention in Viet Nam sought to understand how fathers’ knowledge, attitudes, and involvement in supporting exclusive breastfeeding (EBF) might change after receiving breastfeeding education materials and counseling services. Social and behavior change communications activities included mass media, game show-style community events, group and individual counseling at health facilities and home visits. Compared to fathers in the control group, fathers in the intervention group had higher BF knowledge scores and higher attitude scores reflecting more positive attitudes toward early initiation of BF and 6 months EBF. Fathers in the intervention group were also more likely to report active involvement in supporting mothers to practice EBF during antenatal and postpartum periods. Therefore this community-based education model should be maintained and considered for wider application to mobilize fathers in supporting EBF.