The debate surrounding the ethics of advertising to children generally centres on the age at which children have developed sufficient cognitive resources both to understand the persuasive intent of marketing messages and to critically evaluate them. In this paper we argue that this debate requires urgent updating to take into account recent and significant findings from psychology and neuroscience. Substantial evidence now shows that judgements and behaviours, including those relating to consumption, can be strongly influenced by implicitly acquired affective associations, rather than via consciously mediated persuasive information. Contemporary advertising formats typically targeted at children are particularly likely to 'implicitly persuade' in this way. The implications for the ethical and empirical agenda are profound, pointing the way for a re-evaluation of what constitutes responsible children's advertising, a new research agenda and a new approach to media literacy strategies.