The Institute of Medicine (IOM) report (1999) stated that the prevalence of medical errors is high in today's health care system. Some specialties in health care are more risky than others. A varying blunder/error rate of 0.1-9.3% in clinical diagnostic laboratories has been reported in the literature. Many of these errors occur in the preanalytical and postanalytical phases of testing. It has been suggested that the errors occurring in clinical diagnostic laboratories are smaller in number than those occurring elsewhere in a hospital setting. However, given the quantum of laboratory tests used in health care, even this small rate may reflect a large number of errors. The surgical specialties, emergency rooms, and intensive care units have been previously identified as areas of risk for patient safety. Though the nature of work in these specialties and their interdependence on clinical diagnostic laboratories presents abundant opportunities for error-generating behavior, many of these errors may be preventable. Appropriate attention to system factors involved in these errors and designing intelligent system approaches may help control and eliminate many of these errors in health care.