Many individuals face difficulties when making a career decision. Gati, Krausz, and Osipow (1996) proposed a taxonomy that classifies career decision-making difficulties into three major clusters, which are further subdivided into 10 categories. Based on the proposed taxonomy, they developed the Career Decision-making Difficulties Questionnaire (CDDQ), which has been since adopted and used in moren than 50 countries. Despite its widespread use, the dimensionality of the CDDQ has not yet been fully demonstrated nor its measurement invariance sufficiently confirmed. To test the validity of the internal structure of the CDDQ, the data of 32,556 individuals from Australia, Canada, China, India, South Africa, United Kingdom, and the United States of America, who filled out the English version of the CDDQ on their own initiative, were analyzed. Confirmatory factor analysis supported the original taxonomy and the reliability of the CDDQ scores. The CDDQ also demonstrated scalar invariance across the seven countries, gender, and age, but not career decision status. As career indecision is a major construct in vocational psychology, validating the internal structure of the CDDQ is a fundamental psychometric step with important theoretical, research, and practical implications.