Electronic performance monitoring (EPM), or the use of technological means to observe, record, and analyze information that directly or indirectly relates to employee job performance, is a now-ubiquitous work practice. We conducted a comprehensive meta-analysis of the effects of EPM on workers (K = 94 independent samples, N = 23,461). Results provide no evidence that EPM improves worker performance. Moreover, findings indicate that the presence of EPM is associated with increased worker stress, regardless of the characteristics of monitoring. Findings also demonstrate that organizations that monitor more transparently and less invasively can expect more positive attitudes from workers. Overall, results highlight that even as advances in technology make possible a variety of ways to monitor workers, organizations must continue to consider the psychological component of work.