With the growing application of radioactive materials in medical practice, this short book on the safe handling of radioactive isotopes is of great value. Although it is not intended as a complete manual on radiation safety but merely as a supplement to the work of the radiation protection officer, it contains much useful information. After a brief discussion of the nature of radioactivity and radiation, diagnostic and therapeutic uses of radioisotopes are described. This section is followed by a discussion of radiation hazards, maximum permissible doses, monitoring, safety in a "hot laboratory" and hospital, waste disposal, and decontamination. This book was written for technicians, nurses, doctors, or anyone else working with radioisotopes in a hospital or medical setting. It should help to put radiation hazards associated with the medical uses of radioisotopes into proper perspective for radiation workers.