There is a need to improve students' motivation in science, technology, engineering and mathematics (STEM). Student's academic choices are significantly influenced by parental behaviours and even more so by how those behaviours are perceived by the students. The purpose of this study is to determine the influence of perceived family support/barriers on cognitive-personal variables: self-efficacy beliefs, interest, outcome expectations and goals in a Spanish sample of 10th-grade science-technology students (N = 2359), along with the influence of gender and emotional state effect, through Social Cognitive Career Theory. A path analysis was performed to test the framework model. Findings show that perceived family supports can influence self-efficacy, interests, outcome expectations and goals. Multiple-group analysis showed that weight values did not differ by gender. We concluded that a negative emotional state when faced with science-technology tasks also gives rise to low self-efficacy beliefs about solving these kinds of problems, and therefore a lack of interest in technology and poor outcome expectations and goals. When students perceive parental support around their STEM lessons, their emotional state also improves in these subjects. Overall, these results emphasise the importance of considering parental involvement in career guidance for adolescents.