Career decision-making is a critical task for high school students, yet little is known about how career interventions affect their decision-making skills and self-efficacy. We investigated the outcome of a career intervention in a Chinese high school setting to determine whether it would reduce the difficulties students faced in making a career decision and elevate their self-efficacy in career exploration. A career intervention course was delivered to 413 high school students (228 female, 185 male) who completed a demographic questionnaire, the Major Decision-Making Self-Efficacy Scale (Peng & Long, 2003), and the Career Decision-Making Difficulties Questionnaire-Chinese Version (Shen, 2005) before and after the intervention. Results indicated that the intervention had a positive impact on reducing students' difficulties making career decisions but had mixed results on career self-efficacy. Proactive, systematic, multilevel, and structured interventions over longer periods of time would likely help youth develop their career decision-making skills.