This study examines the impact of Wasta on employee subjective career success, considering the mediating role of internal employability. Based on data collected through a well-designed and validated scale, Wasta was investigated through three dimensions of legitimacy: pragmatic, normative, and cultural. The findings showed a positive relationship between Wasta and internal employability and subjective career success and between internal employability and subjective career success. These results suggest that when Wasta is perceived as a legitimate practice, it boosts an individual’s career success and satisfaction through improving internal employability. This study contributes significantly to the career literature by bridging a gap between informal practices (Wasta) and career trajectory attainment. It enhances our understanding of Wasta, a mechanism of social capital that functions not only as a cultural activity but also as a key potential facilitator of internal employability and career advancement, particularly when perceived as a legitimate practice within an organizational context. Furthermore, this research adds valuable insights concerning the Arabic workplace dynamic that contribute to the cross-cultural understanding of the career success antecedents and informal mechanism of social capital.