This article aims to reflect on the current mental health situation of children, adolescents and young people (NNAJ by its abreviation in Spanish) who are deprived of their liberty in Chile and identify the main obstacles and facilitators that appear at the frontline intervention with this population. In addition, from a critical and situated perspective, the systematization of a practice that proposes art therapy as an intervention tool that facilitates the therapeutic bond between the operators and the NNAJ is presented, and that, in addition, becomes an element of meeting and expression of emotions in a given context and space. The methodological perspective used was qualitative in nature and different techniques of the ethnographic method were used, such as participant observation, field notes and conversations in the context of participant observation. In conclusion, art therapy in prison contexts becomes a tool that favors personal development and emotional expression, achieving greater well-being in young people. In addition, it allows to alleviate certain discomforts associated with the life stories of adolescents, which have been marked by structural violence, precariousness, institutionalization and social stigmatization.