ObjectiveThis study was performed to quantify the quality benefits and staff perceptions of a computerized clinical information system implementation in an intensive care unit. Although clinical information systems have been available and implemented in many intensive care units for more than a decade, there is little objective evidence of their impact on the quality of care and staff perceptions.DesignA longitudinal observational study before and after clinical information system implementation.SettingA 12-bed adult general intensive care unit in a large Australian tertiary referral teaching hospital.InterventionImplementation of a fully featured clinical information system to replace paper-based charts of patient observations, clinical records, results reporting, and drug prescribing.Measurements and Main ResultsThe frequency of clinical adverse events over a 4-yr period using an established reporting system was examined. Pre- and postimplementation staff questionnaires were distributed and analyzed. There were significant reductions in the rates of medication, intravenous therapy, and ventilator incidents. There was a trend toward a reduction in pressure sores. The survey, utilizing a validated questionnaire, demonstrated a positive perception of the clinical information system by nursing staff, with less time spent in documentation and more time in patient care. Nursing staff recruitment and retention improved after clinical information system implementation.ConclusionsImplementation of a fully featured clinical information system was associated with significant improvements in key quality indicators, positive nursing staff perceptions, and some positive resource implications.