The protean and boundaryless career attitudes are concepts that are increasingly relevant as the nature of work and careers are transformed by economic growth, globalization, and technology. These career attitudes that emphasize the individual’s identity and values in career management have not been studied in the Philippine context, even as the economic growth creates new types of jobs and instability in the Philippine labor market. The study validates a well-known protean and boundaryless career attitudes scale, with the view of providing a useful measure to explore these career attitudes in the Philippines. Data from 669 young adults were used to test the structural validity of the four-factor structure of the scale. Confirmatory factor analysis indicated good fit between the four-factor structure and the data, and the four subscales showed good internal consistency. Evidence for the scales’ construct validity was also shown in their relationship with measures of career adaptability, career optimism, perceived career knowledge, and cultural intelligence. Limitations of the study are discussed, but the results point to the growing evidence for the validity and utility of the protean and boundaryless career attitudes in different parts of the world.