The content of the book will be based largely on material derived from a number of undergraduate modules in the author's department, namely: Applied Nuclear Physics, Physics of Medical Imaging, Physics Applied to Physiological Measurement, Laser Photomedicine and Biomaterials Physics, but will also draw on material from elsewhere. The aim is to first cover the properties of biological tissue and then move on to the interactions with the tissue. Diagnostic and then therapeutic techniques will be presented followed by a section with more technical detail for physiological measurement. The material will be separated into a qualitative section bringing out the underlying physics and followed up by a more advanced section with mathematical rigour, where required. This later section will carry a 'Health Warning' indicating it is appropriate for more advanced students.