This paper aims to identify the current situation of the stable union in the Brazilian legal system in the face of controversies and jurisprudential positions, demonstrating the aspects and foundations that designate this new family entity recognized by the Federal Constitution of 1988 in its article 226, § 3 and regulated by Special Laws 8.971/94, 9.278/96 and the Civil Code, as well as pointing out the characteristics that are essential requirements for its recognition. The controversies over the concept of stable union and whether it extends to any and all marital relationships, including homosexual relationships, and what the requirements and rights to be enjoyed by partners in this relationship are, generate legal uncertainty and require specific clarification.