The aim of this paper is to demonstrate the need to implement a specific and adapted procedure in marketing studies among children and adolescents. This procedure is drawn from various work conducted on the universe of childhood as well as from experience acquired in the field. The first part of the paper highlights the reasons justifying a specific approach: I. The specificities of children's intellectual and cognitive processes II. A lower degree of verbal and behavioral control by children and adolescents III. The relationship between marketing professionals and the population to be investigated IV. Relationship among peers. The second part focuses on a description of the techniques adapted to the universe of childhood and adolescence. These techniques comply with the following imperatives: The need for a concrete support, the importance of behavioral observation, the need to take the mother's viewpoint into account, the importance of thwarting tendencies towards conformity or refusal. Each technique is illustrated with tangible examples, sourced from real studies conducted by MSM: video montages, drawings and collages.