We examine gender differences in financial literacy among high school students in Italy using data from the 2012 Programme for International Student Assessment (PISA). Gender differences in financial literacy are large among the young in Italy. They are present in all regions and are particularly severe in the South and the Islands. Combining the rich PISA data with a variety of other indicators, we provide a thorough analysis of the potential determinants of the gender gap in financial literacy. We find that parental background, in particular the role of mothers, matters for the financial knowledge of girls. Moreover, we show that the social and cultural environment in which girls and boys live plays a crucial role in explaining gender differences. We also show that history matters: Medieval commercial hubs and the nuclear family structure created conditions favorable to the transformation of the role of women in society, and shaped gender differences in financial literacy as well. We discuss the changes that are needed to close the gap in financial knowledge among the young.