Drawing on data from a sample of 40 interviews, this paper examines different forms of moral support between adult siblings. Three main results are presented. First of all, the sibling tie does not seem to be very significant for moral support, especially between brothers. However, benevolence is expected between siblings. It expresses itself through some rules, mainly prohibitive, that constitute a frame for moral support. Lastly, because of the structural constraints generated by the kindred's network, the possibility to confide in a sibling or to ask for advice is partly limited. Moral support between siblings is thus characterized by two principles of action that are potentially contradictory: parity and benevolence.