This report covers guidance on how to approach the radiation protection issues which may arise following brachytherapy of the prostate using permanent implantation of radioactive iodine-125 seeds. It is intended to be read by scientific staff, but will also have valuable information for medical practitioners who perform brachytherapy. The report aims to provide a common approach to these issues in the UK to ensure uniform compliance with national and international regulations. Starting with a brief overview of the prostate brachytherapy procedure, the report continues with an outline of the relevant information and guidance which must be given to the appropriate people on patient discharge. An in-depth chapter focuses on the assessment of risks and environmental impact associated with cremation of the patient’s body post implant, including when it is safe to cremate and recommendations on procedures when it is not. A further chapter addresses the risks around post implant surgical intervention in the pelvic region. Subsequent chapters cover additional requirements for the brachytherapy centre and the information which should be disseminated to the relevant people. The appendices include example dose calculations and example documentation. Report 106 will be a valuable reference for all radiotherapy departments undertaking brachytherapy and to all medical physics departments who provide radiation protection services.