Sex differences in the salience and meaning of kin relations for contemporary Canadians were examined in two studies. In study 1, 24 opposite-sex adult sibling pairs were asked to reconstruct their kindreds as fully as possible, following a computerized menu. Sisters almost invariably recalled more relatives than did their brothers, especially living and matrilateral relatives. In study 2, a questionnaire administered to 150 female and 150 male undergraduates explored the relevance of kinship to characterizations of the self ( Who are you? ) and to nominations of one's closest social relationships. Women were much more likely than men to refer to their kinship statuses in characterizing themselves (I am a daughter, a sister, etc.), whereas 28% of men and only 8% of women mentioned their surnames (I am a Smith, Jones, etc.). Women and men were about equally likely to name a relative, as opposed to a mate or friend, as the person to whom they feel closest, but women more often nominated a parent (especially mother) and men a sibling (especially an older sister). These sex differences are discussed in relation to possible differences in how women and men make use of family ties.