Intervention programs creating awareness among girls about the wide range of career opportunities in the Information and Communications Technology (ICT) field are conducted in many countries to tackle the problem of female under-representation in ICT. The long-term effects of these programs, however, are rarely evaluated which hinders the understanding of how they could be improved, their value and success factors. The goal of this study is, therefore, to investigate the longitudinal influence of one such program held biennially in Australia since 2006, by analysing survey data both quantitatively and qualitatively (n = 153). The results show that continuous study of an ICT subject at school by girls positively influences both their intention to choose a career in ICT and the actual choice of ICT as a university major. Moreover, the attitude towards the intervention program has a weak, but significant positive effect on the decision to study ICT at school.