The paper demonstrates the important role research can play in the development of an advertising campaign aimed at children. Following increasing concern about the safety of children on the roads, a detailed set of procedures to guide children across the roads safely, was developed in the United Kingdom. The set of procedures, called the Green Cross Code was promoted to children aged 5 to 12 (in terms both of teaching and encouragement to use the Code) by a variety of means, including advertising aimed at children themselves. Initially the emphasis of Green Cross Code advertising to children was placed on teaching the Code as a set of rules to be followed. These detailed rules form a very complex communication to children, with particular difficulties at the lower end of the age range. A considerable amount of research has been carried out in connection with this advertising campaign and the paper describes the methodology employed in detail.