Laboratory medicine has undergone a sea change, and medical laboratories must now adapt to, and meet new, customer-supplier needs springing from shifts in the patterns of disease prevalence, medical practice, and demographics. Managed care and other cost-containment processes have forced those involved in health care to cooperate to develop a full picture of patient care, and this has affected clinical laboratory objectives, the main focus now being on improvement in medical outcomes. More recently, the resource shortages in health care and results of cost/effectiveness analysis have demonstrated that the value of a laboratory test must be ascertained not only on the basis of its chemical or clinical performance characteristics, but also by its impact on patient management, the only true assessment of the quality of testing being quality of patient outcomes. The time is ripe for changing the vision of laboratory medicine, and some of the reasons for this are the availability of results in real-time, the introduction of more specific tests, and the trend to prevent diseases rather than cure them. The information from laboratory tests designed to evaluate biochemical or genetic risk and/or prognostic factors cannot be replaced either by physical examination and/or the assessment of symptoms. Today, the importance of laboratory scientists must be proven in three broad areas: a) guaranteeing the quality of tests, irrespective of where they are performed; b) improving the quality of the service; c) maximizing the impact of laboratory information on patient management.