For many years, researchers have used the theory of planned behaviour (TPB) in order to suggest that human behaviour is greatly influenced by people’s preferences and attitudes, social norms, perceived behavioural control and intentions to act (Ajzen, 1991; Armitage and Conner, 2001) , . Over the last 20 years, this theory has been extended in order to include additional variables such as social conflict (Olsen, 2004) , social norms, social group and social identity (Terry, Hong and White, 1999) . In the area of food consumption behaviour, social variables seem to be of significant importance in terms of the consumption of meals in the home (Olsen, 2001) , and some social variables (social norms and descriptive norms) appear to have a consistent influence across different cultures (Tuu et al., 2008) . However, most research that uses TPB in order to explain food consumption behaviour was conducted in developed countries and Western cultures (Armitage and Conner, 2001) . This study has been designed in order to provide an insightful understanding of the roles of family interactions (norms, conflict and identity) in explaining Vietnamese families’ fish consumption behaviour.