The mediation of career decision-making self-efficacy on the link of ambiguity tolerance (AT) with career indecision was examined in a sample of college students ( N = 253). It was hypothesized that AT could help reduce career indecision through increasing career decision-making self-efficacy, where this effect would vary by different types of indecision. Results supported the differential mediation hypothesis, finding that career decision-making self-efficacy mediated the link of AT with lack of motivation, general indecisiveness, lack of information, and inconsistent information. The mediation effect of career decision-making self-efficacy on the link of AT with lack of motivation was relatively weak. The implications of this study are discussed and suggestions for future research are provided.