Rational-choice approaches to consumer behaviour neglect the influence of habitual factors. Previous research outside the food choice area has found that habitual factors tend to dominate when the target behaviour is performed often and in stable contexts, whilst deliberative factors tend to dominate when the target behaviour is performed rarely and in unstable contexts. In the food choice area, only little research exists that would allow a similar assessment. As part of the SEAFOODplus project, representative surveys were conducted in Belgium, Denmark, Spain, the Netherlands, and Poland (total N = 4800). Extended theory of planned behaviour specifications were estimated that included habit as an exogenous variable. The results indicated that habit predicted attitude, subjective norm, and perceived control far better than these could in turn predict intention and behaviour, apparently reflecting different facets of satisfaction with the outcomes of past behaviour episodes. The standardised total effect of habit on behaviour was 0.41 (Belgium), 0.17 (Denmark), 0.30 (Spain), 0.21 (Netherlands), 0.21 (Poland) whilst the standardised total effect of intention on behaviour was 0.13 (Belgium), 0.18 (Denmark), 0.10 (Spain), 0.16 (Netherlands), 0.00 (Poland). Although no general answer may exist to the question whether habitual or deliberative factors are more important in food consumer behaviour, habits appear to dominate behaviour in the domain of seafood consumption.