The purpose of this study was to develop a Korean Career Indecision Inventory (K-CII) applicable to Korean university students. A total procedure of five steps was conducted to develop and validate the scale. The K-CII comprises five factors: Lack of Career Information, Lack of Necessity Recognition, Lack of Self-Identity, Indecisiveness, and External Barrier. The External Barrier includes the items of financial difficulty, parents, the tendency for academy cliques to dominate, and age, representing factors specific to Korean culture. The same five factors consistently emerged in Steps 2, 3, and 5. In addition, the results of the confirmatory factor analysis in Step 3 showed that the five-factor solution had a good fit to the data. Internal consistency reliabilities and test-retest reliabilities showed that the K-CII was reasonably reliable. The K-CII factors were significantly related to similar constructs such as decidedness and certainty factors of career maturity, supporting the convergent validity. The K-CII total score and factors also showed significant correlations with various mental health variables, supporting the criterion-related validity of the K-CII. Finally, the implications of the results and the need for future studies were pointed out.