High-performance work systems have been widely adopted in the workplace. Previous research on high-performance work systems debated whether the generated effects are mutual gains or conflicting outcomes for employers and employees. Drawing on the job demands and resources model, this conceptual study proposes that high-performance work systems can be both beneficial and harmful by eliciting distinct perceptions in employees. Specifically, perceptions of job resources are the positive and perceptions of job demands are the negative mechanism whereby high-performance work systems affect employee job performance. This research further proposes that servant leadership strengthens the positive impact of high-performance work systems, whereas directive leadership strengthens the negative impact. Overall, this conceptual research provides new insights into the research on high-performance work systems.