Kinship and family are important themes in anthropology. This paper tries to discuss the changes and ontological questions that has oriented this discipline trough the years. From an historical point of view, we will revisited the classical approaches to the contemporary theories to oriented our discussion towards the new realities that are transforming relationships of family, kinship and parenthood. With a special regard we will use the comparison between adoption and assist reproductive technologies to enlighten the contributions that guide us to a better understand of these complex relationships that we call family.