The relationship between position in a peer network (liking, disliking, popular, unpopular), its perception (metaperception), and loneliness were studied in a sample of 629 pupils (221 from grade 5 and 408 from grade 6 of primary school). The analyses conducted (Multiple Indicators, Multiple Causes Models - MIMIC - and SEM) first of all showed that among boys loneliness is mostly linked to unpopularity and among girls to disliking. These results prove the existence of cross-gender differences in the "location" of the source of stress that impacts loneliness: a fixed reputation of being unpopular among boys and negative dyadic relationships among girls. The second noteworthy result is that the negative assessment criteria of position in the peer network hierarchy are more important than the positive ones. This pattern holds with both, boys and girls. The third important result is that metaperception mediates between position in the network and loneliness. However, this relationship only appears in he case of the disliking criterion.