Traditional Chinese medicine (TCM) differs from its Western counterpart in a number of ways. One of the more striking ways involves a conceptually oriented diagnostic system that relies more on the clinician's reading of the patient's symptoms and signs than on laboratory findings. Because highly individualized TCM treatment plans emanate directly from its diagnostic system, a necessary condition for conducting clinically relevant TCM efficacy trials rests on the answer to a simple question: How consistent are different TCM practitioners at making the same TCM diagnoses and prescribing comparable treatment regimens for the same group of patients? Unfortunately, this question has not been adequately investigated, nor has the related question: Could the TCM diagnostic process be enhanced by access to modern biomedical tests? The purpose of this paper, therefore, is to discuss a number of the conceptual and methodological issues involved in the design of a recently funded NIH study whose primary purpose is to address these 2 questions.