The aim of this work is to provide a cross-cultural contribution to the study of gender differences in adolescent mood by providing the results of a random sample of 165 Argentinian boys and girls studied longitudinally by means of a survey at 13-14, 15-16 and 17-18 years old. Using Rosenberg's Depressive Affect Scale, the gender difference, larger than that of many first-world samples, is significant at 15-16 and the gap increases at 17-18. It is already present at 13 in another sample in which Kovacs' Child Depression Inventory was applied. Girls reporting high family warmth, high self-esteem, low anxiety and who do not choose a friend as the most admired person at 13-14 have a better mood on average through adolescence while high self-esteem and weight satisfaction at 13-14 exerts this kind of effect in boys. A buffering effect of self-esteem on levels of girls' dysphoria was also demonstrated. (C) 2001 The Association for Professionals in Services for Adolescents.