Abstract The future of healthcare delivery systems will depend on their ability to provide the best care at the least cost. In the clinical laboratory, this translates to ensuring that decreased test use means appropriate use. The latter is unlikely to occur unless clinical laboratories provide practicing physicians with advice on test strategy and interpretation of results. Effective clinical laboratory consultation requires an identification with clinical problems. Important components of the identification process are an appreciation of the probabilistic rather than deterministic nature of the relation of clinical and laboratory data to disease and the inevitable tradeoff between false negatives and false positives that clinical circumstances demand. Institution of consultation services requires that the clinical laboratory adopt a proactive approach to advocating test strategy and interpreting results. Consultation on test strategy is likely to be facilitated by further developments in practice guidelines and by advances in informatics and telemedicine.