Society has moved out of the historical context of group marriage into the monogamous model of marriage, 

with the aim of ensuring biological paternity, a crucial element for the head of household to give his inheritance to the legitimate

child through inheritance. Over time, other forms of family arrangements emerged and were recognized by the state, 

such as the stable union and the single-parent family. However, despite not being included in the constitutional text or in the 

infraconstitutional legislation, simultaneous families were formed and nowadays they constitute a factual reality, whose search

for legal recognition has grown. No wonder there are numerous demands in this regard within the judiciary. 

Due to the lack of a specific rule on the subject, each court decides according to its own convictions, 

sometimes treating this relationship as a de facto society, sometimes as a family entity. In order to provide legal certainty and 

uniformity in legal decisions, this dissertation proposes to study art. 226 of the Brazilian Federal Constitution, analyzing whether 

it lists a taxative or merely exemplary list of family entities recognized by the national legal system. This paper was done 

regarding constitutionalization of Civil Law, also as the constitutional order inaugurated with the Federal Constitution of 1988, 

which granted normative force to the general principles. Finally, it is intended to determine whether or not simultaneous unions 

can be legally recognized as family entities, receiving or not the special protection of the State.