While the constructs of protean and boundaryless careers have informed career theory for years, rigorous empirical examinations of these career models have lagged behind. This study seeks to redress this situation by constructing and developing four new scales to measure protean and boundaryless career attitudes. The scales related to protean career attitudes measure self-directed career management and values-driven predispositions. The scales related to boundaryless career attitudes measure boundaryless mindset and organizational mobility preference. The initial validation of these scales, consisting of three studies, demonstrates their reliability and validity.