The clinical information system (CIS) is becoming more common in intensive care units. These systems have the ability to record, store, and retrieve large amounts of clinical patient data with great ease. This should greatly facilitate outcomes research and quality assurance. Unfortunately, there is not much information available about the accuracy of the data coming from these systems. True accuracy of a patient record requires both completeness of data and correctness of data as well as legibility. Automated systems are clearly superior to human entered data in terms of completeness and legibility but the correctness of entered data remains unclear. There are aspects of automated data entry that facilitate erroneous data entry. This article reviews the existing literature on accuracy of CISs with special attention to the qualities of automated data entry that can lead to false data. Additionally, data are presented from a newly published study by the author evaluating the validity of data from a commercially available CIS.