The purpose of the study was to examine if the use of EAP services was associated with improved work effectiveness. Twenty different EAP providers contributed a convenience sample of 3,187 employee clients who had completed the Workplace Outcome Suite (WOS) 5-item measure both at before use of the EAP and a 90-day follow- up period after EAP use. All five items showed statistically significant positive change, but the greatest amount of improvement was found for work absenteeism, work presenteeism and work distress with less sizable improvements for work engagement and life satisfaction. These results offer evidence that EAP services can improve the workplace performance of employees.