The present investigation presents as a general objective to determine how shared ownership through extrajudicial conciliation affects the principle of the best interests of the child, in Peru. The type of research according to its level is correlational; according to its purpose, basic; and according to their approach, qualitative. The first sample is represented by 8 extrajudicial conciliators, 5 civil lawyers and 5 psychologists, the same who specialize in family law and care for children and adolescents, the second sample is made up of 20 parents, the third sample includes the pertinent legislation in relation to the study variables, and sample four made up of jurisprudence and doctrine related to the custody of minors. The main result determined that the Extrajudicial conciliators do not have the necessary tools to know how to guide a shared tenure agreement, since, neither in the E...