We argue that the most‐promising area of clinical application of microarrays in the foreseeable future is the diagnostics and monitoring of infectious diseases. Microarrays for the detection and characterization of human pathogens have already found their way into clinical practice in some countries. After discussing the persistent, yet often underestimated, importance of infectious diseases for public health, we consider the technologies that are best suited for the detection and clinical investigation of pathogens. Clinical application of microarray technologies for the detection (...) of mycobacteria, Bacillus anthracis, HIV, hepatitis and influenza viruses, and other major pathogens, as well as the analysis of their drug‐resistance patterns, illustrate our main thesis. BioEssays 30:673–682, 2008. © 2008 Wiley Periodicals, Inc. (shrink)