The report is an update and expansion of the earlier IPEM Report 76, which covered UV and blue-light phototherapy. The content has been revised in the light of other published work and changes to clinical practice. Starting with a chapter on the physics and biology of UV phototherapy, subsequent chapters deal with the principles of UV phototherapy, UV measurement and dosimetry, and UV safety. Following this there is a new chapter on photodynamic therapy, providing an introduction to the applications, mechanisms of action, sources, dosimetry, measurement, meters, field size and uniformity, and safety. The final section of the book deals with blue-light phototherapy, with chapters on the physics and biology of blue-light phototherapy, its application to the treatment of neonatal jaundice, and the treatment of Crigler-Najjar Syndrome. The final chapter discusses bluelight safety issues. There is an extensive reference section. This publication is aimed at clinical scientists working in phototherapy physics in any of its aspects, but is likely to be of interest to other clinical groups needing to access source material on these therapies.