Emerging technologies such as spectroscopic gas sensing can benefit greatly by the development of robust, high-power semiconductor lasers emitting in the mid-infrared spectrum. Great progress has been made with these lasers, especially at wavelengths shorter than about 3 micrometers . Lasers with wavelengths longer than about 3 micrometers , however, suffer from nonradiative recombination mechanisms. As such, they continue to operate with modest power levels at temperatures below 150 K. Practical systems, however, demand higher- temperature operation, preferably above 250 K. The challenge, then, is to suppress the nonradiative recombination mechanisms while enhancing light emission of these narrow- bandgap materials. This paper outlines the progress made to date, including material-growth advances and device-structure designs which have enabled significant advances in the technology. The obstacles to higher-temperature operation, such as Auger recombination, will be identified. The tools being used to overcome these obstacles will also be discussed, including band-structure engineering. Finally, future research in this fertile area will be suggested which could augment current efforts.