Medical licenses issued by the Nuclear Regulatory Commission contain the restriction that patients who are being treated with 131I should not be discharged from the hospital if the body burden is greater than 30 mCi (1,110 MB1). It is argued that there are no sound data supporting the theory that a patient receiving more than 30 mCi (1,110 MB1) of 131I is dangerous to others. This limitation may result in the use of lower, less effective doses of 131I, so that expensive, unnecessary hospitalization can be avoided. The need for adequate radiation safety programs that will advise patients and their families of the necessary precautions following therapy with 131I is discussed.