ICRP Publication 84 concerns the management of pregnant patients as well as pregnant workers in medical establishments where ionising radiation is used. Thousands of pregnant patients and medical radiation workers are exposed to radiation each year. Lack of knowledge is responsible for great anxiety and probably unnecessary termination of many pregnancies. This report discusses how to deal with these problems. It is written primarily for physicians, but will also be useful for medical and health physicists, nurses, technologists, and administrators. It is not intended as a complete reference work, but rather to provide a practical approach that can be used in varying situations.