The purpose of this study was to examine the cross-cultural validity of the effects of attachment, career-choice pessimism, and intrinsic motivation on career adaptability (CA) in American (n = 198) and Korean (n = 294) college students. We hypothesized that the association between attachment and CA is sequentially mediated by career-choice pessimism and intrinsic motivation in both samples, and the results supported the hypothesized multilevel model. These results have important implications for practice to promote CA for college students across cultures by providing evidence for cross-cultural validation of factors influencing on CA.