A transition from elementary to high school represents a very profound change and a potential source of stress, as it often requires young adolescents to make significant professional decisions. This topic was the focus of the present study in which 303 Croatian students attending their final year of elementary school completed measures of career decision self-efficacy, emotional stability, emotional competence, and concerns regarding the upcoming transition. The results indicated emotional competence as a statistically significant predictor of career decision self-efficacy, whereas emotional stability was revealed as a significant predictor of career concerns. Furthermore, a moderating effect of gender and a mediating role of career decision self-efficacy were revealed in this context. These findings provide novel evidence regarding the complex relationship between individuals’ vocational self-beliefs and emotional processing and may be informative for vocational guidance interventions targeted at young adolescents undergoing similar educational transitions.