The purpose of this study is to investigate the long-term stability of the positive effects obtained through career guidance. This study focussed on the longitudinal effects of career guidance on students' major satisfaction. Data from the Korea Education and Employment Panel (KEEP) were analysed by applying SPSS 18.0 and AMOS 18.0 to investigate the mediation effect of students' self-efficacy between career guidance and students' major satisfaction. Results indicated a continual increase of self-efficacy in long-term stabilisation with regard to students' satisfaction with their academic majors. This study quantitatively investigated the long-term stability of the positive effects obtained through career guidance. Although the findings were somewhat tentative, there was preliminary support for the influence of three critical ingredients: counselling, career information and professor guidance in all types of career guidance. However, additional research is needed to identify which students benefit from which career guidance and under what circumstances.