Taking a behavioral perspective on high-performance work systems (HPWS), we examine the role that organizational trust plays as a key psychological mechanism linking HPWS and firm capabilities (customer response capability and internal process capability). We further draw on configuration theory and explore how the fit between organizational culture and HPWS can be mutually reinforcing, leading to superior firm capabilities. Based on multisource data collected from 2094 employees in 500 companies in South Korea, the results show that HPWS are positively related to firm capabilities and that the link is fully mediated by organizational trust. HPWS show significant interaction effects with adhocracy, market, and clan cultures on firm capabilities but show no interaction effects with hierarchy culture. These findings highlight the importance of organizational trust and organizational culture aligned with human resource practices in the successful implementation of HPWS.Keywords: customer response capability, high-performance work systems, internal process capability, organizational culture, organizational trust Key points 1 High-performance work systems (HPWS) were positively related to firm capabilities (customer response capability and internal process capability) by strengthening employees' trust in the organization. 2 It is important to cultivate adhocracy, market, or clan cultures prior to implementing HPWS to achieve organizational goals. 3 Management's decisions and actions that consistently support the focus of HPWS on human capital development are likely to nurture organizational trust and thereby encourage successful implementation of HPWS.