Hyperspectral imaging (HSI) is an emerging imaging modality for medical applications, especially in disease diagnosis and image-guided surgery. HSI acquires three-dimensional data set called hypercube with two spatial dimensions and one spectral dimension. Spatially resolved spectral obtained by HSI provides diagnostic information about the tissue physiology, morphology, and composition. This chapter presents an overview of literature on medical hyperspectral imaging (MHSI) technology and its applications. The aim of this chapter is threefold: an introduction for those new to the field of MHSI, an overview for those working in the field, and a reference for those searching for literature on a specific application. This chapter starts to review the basic mechanisms of MHSI and then classify MHSI technology based on acquisition mode, spectral range and spatial resolution, measurement mode, dispersive devices, detector arrays, and combination with other techniques. Image analysis methods for MHSI are summarized with preprocessing, feature extraction and selection, image classification methods. The part on applications is a reference of the literature available on disease diagnosis and surgical guidance. MHSI applications on cancer detection, cardiology, pathology, retinal imaging, diabetic foot, shock, tissue pathology, mastectomy, gallbladder surgery, renal surgery, and abdominal surgery are reviewed. This chapter closes with a discussion on future challenges and perspectives.