This thesis addresses discourses on peace and violence in Rio de Janeiro and how they are assimilated and reproduced by children. Its content derives from ethnographies conducted at two schools in different regions of the city, which allowed the observation of moments of seriousness and relaxation in children s daily lives. The first school is located in the middle-class neighbourhood of Tijuca and has a high tuition fee; the second one is a municipal public school located in Complexo da Maré, a region frequently threatened by conflicts between the gangs and the military police during the period of this research. In the interaction between teacher and students, the category violence presents itself and is countered by the culture of peace. Violence can be condemned or justified at each social context especially according to the power relations between the executor and the victim. The media are seen here as possible influencers of social imaginaries and as a base for children s play, taking into account the child s capacity of inventing and transforming culture. This work reinforces the need for a plural analysis of the category violence, signalizing coercive dynamics that operate in the studied social groups.