We report on the development of a novel thermography technique, integrated Raman – IR thermography, illustrated here on AlGaN/GaN electronic devices. As it is a generic technique future application to Si, GaAs and other devices is anticipated. While IR thermography can provide fast temperature overviews, its current use for many of today’s technologies is complicated by the fact that it does not provide the spatial resolution needed to probe sub-micron/micron size active device areas. Integrating IR with micro-Raman thermography, providing temperature information with ~0.5 µm spatial resolution, enables unique thermal analysis of semiconductor devices to a level not possible before. This opens new opportunities for device performance and reliability optimization, and failure analysis of modern semiconductor technology, in research, development, and quality control / manufacturing environments.