An experimental study was conducted to examine the impact of multiple monitors on user performance and multitasking. Forty-three participants were assigned to two groups: a multi-monitor group and a single-monitor group, to carry out a series of tasks. Both quantitative and qualitative data were collected and analyzed. Results indicated that those who used the multi-monitor display were more inclined to multitask, and scored higher on performance measures than those using the single monitor. Interviews from the participants validated the quantitative results and provided additional insights on usability issues of multi-monitor displays.