Implementing electronic performance monitoring in the workplace might improve the efficiency and quality of employee data that are collected. These intended benefits might be discounted or even eliminated if employees have a negative reaction to the monitoring process. The goal of this exploratory study was therefore to investigate which electronic performance monitoring techniques and monitoring characteristics are associated with negative employee reactions using survey responses from 190 student workers. Results showed that close performance monitoring (via cameras, data entry, chat and phone recording) had significant negative effects on job attitudes such as job satisfaction and affective commitment. Similar effects were observed for employee self-efficacy and perceived control. Attitudes were furthermore negatively impacted when the monitoring was focused on individuals and unpredictable, which also reduced organisational citizenship behaviour while continuous monitoring reduced self-efficacy. These findings suggest that the benefits of close monitoring may be overshadowed by negative employee reactions.