The right of retention is the faculty granted to the creditor of a legal relationship to retain something owed to its rightful owner until the satisfaction of a credit due to improvements introduced therein. In other words, it is a legitimate reason of refusal of return the thing to its rightful owner, with the consequent prolongation of possession beyond the moment that should cease. However, the matter is subject to unsystematic and disjointed treatment in Brazilian law, with traces of the criminal typification of arbitrary use of own reasons. Therefore, an examination of the institute is proposed, with Article 1,219 of the Brazilian Civil Code as the principled basis, specially related to the subjectivity of good faith indicated by the legislator, seeking to identify the possibility of applying the institute beyond aprioristic formalisms and historical dogmatisms and as and as a self-protection form.