Since this subject was last reviewed in the American Journal of Respiratory and Critical Care Medicine (1), new diagnostic tests for tuberculosis have been approved for use in the United States, Europe, and other industrialized regions, and there has been significant clinical experience with their use. In addition, several other new diagnostic assays have been studied and may be nearing approval by the Food and Drug Administration (or similar agencies in other countries) for routine clinical use. This commentary will review the need for new diagnostic tests for tuberculosis, examine the status of currently available tests and of several promising tests in development, and discuss potential scenarios in which such diagnostic tests might be used.