Purpose: Agile project management methods gain increasing attention of practitioners while they often remain neglected by scholarly research. Specifically, there is little known about how performance factors of agile firms differ from those of traditional firms. Scholars argue that these factors often relate to a firm’s human resource management (HRM). This study aims to analyze and compare the HRM architectures in agile and traditional project-based organizations that lead to high firm performance. Design/methodology/approach: The authors apply fuzzy-set qualitative comparative analysis on data of 154 project-based organizations of diverse professional service industries in Russia. Findings: This study’s findings suggest that HRM architectures of high-performance agile firms imply a broad use of ability-, motivation- and opportunity-enhancing practices and a high degree of HRM process centralization, while traditional firms adopt more diverse HRM architectures. Originality/value: Based on this study’s results, the authors stress the importance of ensuring a good fit between a company’s project management approach and HRM architecture. The revealed configurations may also provide guidance for practitioners on designing effective HRM architectures in project-based organizations.