With data collected from 632 manufacturing firms in South Korea, we investigated (1) the relationship between high-performance work systems (HPWSs) and firm performance, and (2) the moderating effect of the human resource (HR) function’s influence on the relationship between HPWSs and firm performance. Our findings showed the existence of both the main effect of HPWSs, supporting the universalistic perspective, and the moderating effect of the HR function’s influence, supporting the contingency perspective. Based on the findings, we concluded that HPWSs can be regarded as universal or best practices; at the same time, the presence of an influential HR function may intensify the effect of HPWSs on firm performance. This study contributes to the debate over the respective merits of the universalistic and contingency perspectives by showing that the two perspectives are not necessarily incompatible; rather, they can be complementary.