The scarcity of women in ICT-related studies has been systematically reported by the scientific community for many years. This paper has three goals: to analyze gender differences in self-concept of computer and math abilities along with math performance in two consecutive academic years; to study the ontogeny of gender differences in self-concept of computer and of math abilities and math performance across subject areas; and to contrast the role these variables play in predicting ICT-related studies over 2 years. 900 (M = 15 years, s.d. = 1.73) and 424 (M = 16 years, s.d. = 0.49) Spanish secondary students participated at both times. Self-concept of computer ability is higher in boys at both times; furthermore it decreases in girls and increases in boys across time. At time 2, boys have a higher self-concept of math ability, despite the lack of gender differences in math performance. Participants have a higher self-concept of math ability and math performance at time 1 than at time 2. Self-concepts of computer ability predict the intention to pursue ICT-related studies and mediate the association of gender with the intention to pursue ICT-studies. (Contains 4 tables and 3 figures.)