Career decision-making significantly impacts high school students' academic and career trajectories. Although career interventions are recognized as important, gaps persist, particularly in programs targeting Chinese high school students and the inconsistent findings on gender differences. This study evaluated the effects of career courses and group counseling on Chinese high school students. Study 1 assessed the impact of a career course on 308 first-year high school students. The course increased self-efficacy but did not reduce career decision-making difficulties. Notably, gender differences were observed: male students reported increased difficulties, while female students showed a decreasing trend. Study 2 combined a career course with group counseling. The combined intervention significantly reduced career decision-making difficulties, with no gender differences. These findings suggest that career courses boost self-efficacy but adding group counseling helps address career decision-making difficulties. Our study also highlights the need for gender-responsive strategies.