In the past 50 years women have gradually caught up with, and even surpassed, men in educational achievement. Nevertheless, women seem to lose their advantageous position as soon as they enter the labour market. Compared to men they earn less, work fewer hours a week and are more often employed with temporary contracts. These differences are frequently attributed to a differential career investment made by men and women. Previous studies on labour market outcomes mostly focus on the effect of the level of education. Nevertheless, this can not explain gender differences as women are generally higher educated than men. It is well-established, however, that men and women tend to choose different subjects in school. While men are over-represented in the 'harder' and more technical subjects, women dominate the 'softer' subjects like health and welfare. The subject choices young people make in secondary and/or higher education might explain the lower labour market opportunities of women since these different subjects lead to the acquisition of different skills and competences. Using data from the longitudinal SONAR-survey, which registers the transition from school to work of Flemish youth, we examine to what extent different subject choice influences the gender differences in labour market positions in both the first job and at the age of 26. Since previous analyses have shown that patterns of family formation have an effect on the labour market position, we control our models for these patterns.