To evaluate the impact of Computerized Provider Order Entry (CPOE) on workplace stress and overall job performance, as perceived by medical students, housestaff, attending physicians and nurses, after CPOE implementation at Penn State—Milton S. Hershey Medical Center, an academic tertiary care facility, in 2005. Using an online survey, the authors studied attitudes towards CPOE among 862 health care professionals. The main outcome measures were job performance and perceived stress levels. Statistical analyses were conducted using the Statistical Analytical Software (SAS Inc, Carey, NC). A total of 413 respondents completed the entire survey (47.9 % response rate). Respondents in the younger age group were more familiar with the system, used it more frequently, and were more satisfied with it. Interns and residents were the most satisfied groups with the system, while attending physicians expressed the least satisfaction. Attending physicians and fellows found the system least user friendly compared with other groups, and also tended to express more stress and frustration with the system. Participants with previous CPOE experience were more familiar with the system, would use the system more frequently and were more likely to perceive the system as user friendly. User satisfaction with CPOE increases by familiarity and frequent use of the system. Improvement in system characteristics and avoidance of confusing terminology and inconsistent display of data is expected to enhance user satisfaction. Training in the use of CPOE should start early, ideally integrated into medical and nursing school curricula and form a continuous, long-term and user-specific process. This is expected to increase familiarity with the system, reducing stress and leading to improved user satisfaction and to subsequent enhanced safety and efficiency.