The protean career orientation is descriptive of workers who show self-directedness and values-driven behaviors toward professional advancement. Such characteristics have been highly demanded from professionals in the past decades, evidencing their identification and development relevance. Considering that identifying construct structure and invariance is critical for effective measurement and both theory-building and practice, this study aimed to adapt and obtain internal and external validity evidence of the Protean Career Measure to the Brazilian context. Participants were 558 professionals (67% women). Exploratory and confirmatory factor analyses resulted in a unidimensional model. They provided evidence of configural, metric, and scalar invariance between men and women. Also, they showed convergence between the protean career orientation and career models based on other characteristics (kaleidoscope, adaptability, and work engagement). Finally, results showed that the protean orientation tends to be higher, according to the participants' life/career stages' advancement. We discuss the application for research and interventions.