The aim of this article is to examine the impact of polygamous family system on the aggressiveness of the teenage girl on the mother. In Cameroon, as in many other sub-Saharan Africa countries, the concept of polygamy is still highly valued, but faced with conflict and suffering between parent and teenager, especially in the absence of the father. The exploitation of the two clinical viewpoints helped highlight the reality by which the absence of the father in a polygynous family is a source of conflict between the girl and the mother and this is a source the dislocation of the family structure. This backdrop is perceived as an object of family disintegration. But that said, it remains important that the acknowledge that polygynous family is not in essence a source of conflict. The lack of emotional investment of father towards the girl leaves the family in a deep emotional suffering state leading the teenage girl in a process of deconstruction of acquired values that cause the violence of this girl towards her mother, running away from home, aggression, drug consumption.