This study explores central questions related to the connections between a firm's HR system and its ability to exhibit organizational ambidexterity. We build off of existing work on the behavioral view of ambidexterity to assess the extent to which the utilization of certain HR practices may be linked to a context marked by discipline, stretch, trust, and support. We further argue that these disparate practices may be combined into a single high performance work system (HPWS), which allows the firm to achieve both the alignment and adaptability necessary to produce ambidexterity. As such, we examine HPWS as a systematic tool for enhancing organizational ambidexterity. We explore this link using data from 215 high-tech SMEs and find that HPWS utilization is positively related to a measure of organizational ambidexterity. In turn, ambidexterity mediates the relationship between HPWS utilization and firm growth.