The purpose of the present research was to develop and validate a measure of motivation toward career decision-making activities, the Career Decision-Making Autonomy Scale (CDMAS). The CDMAS is designed to assess the constructs of intrinsic motivation, identified regulation, introjected regulation, and external regulation. A longitudinal study was used to develop and validate the CDMAS. Overall, results show that the CDMAS is composed of four internally consistent factors. The construct validity of the scale is also supported by (a) a quasi-simplex pattern of correlations, (b) correlations with personality variables and vocational constructs, and (c) convergent and divergent correlations. In sum, the CDMAS represents a valid self-report measure of intrinsic motivation, identified regulation, introjected regulation, and external regulation toward career decision-making activities.