The mid–infrared (mid–IR) should be a fruitful area for medical research and instrumentation since this is the region where the most identifiable molecular molecules absorb and radiate. Due to the unique specificity of a biological molecule's spectrum in the mid–IR, semiconductor lasers in the mid–IR have a unique advantage over ultraviolet and visible or near–IR lasers. Small room–temperature laser diodes can be used in small hand–held, portable, and hopefully inexpensive, medical devices for rapid measurement, possibly in patient–operated home–care devices. Since the mid–IR radiation can be connected with otherwise invisible chemical processes, it becomes possible to watch the biochemical processes of life reveal themselves. Until recently, work in this region had been handicapped by lack of sources, detectors and optical materials, but this is changing, as this conference shows, and important new directions lie ahead.