[en] Benefit and risks in radiodiagnostic examination, either with X-rays or with radioactive isotopes, can be expressed in restored health and health impaired by radiation or: lives saved and estimated lives lost as a result of genetic or somatic radiation damage. Published data on benefit-risk comparisons for mass stomach and chest surveys show a considerable benefit surplus. It is demonstrated that this is also true in the case of clinical examinations of the sick. Efforts should be concentrated on better ways and means to reduce the number of diagnostic errors. Risk estimates should be made as realistic as possible