The article seeks to understand and diagnose the use of the mediation institute as a way of treatment for collective urban land conflicts, from the perspective of the Public Defender’s Office. It is used a single case report method of the conflict involving the interests of the Bom Sossego Community, located in the city of Marituba, in the state of Pará. The research has a descriptive-analytical characteristic, the survey carried out was essentially documentary and a narrative bibliographic review was performed. It is concluded from the study and analysis of the case presented that the use of the self-composition instrument can be important and effective for the treatment of the conflict and to transform and pacify the relationship between the actors involved, and also able in the structural reforms to achieve access to justice and to the implementation of public policies that guarantee the right to adequate housing and development through the expansion of freedoms and capacities.