A summary is given on international guidance on intervention levels in circumstances in which remedial actions might be considered in nuclear accident situations. The nature and limitations of international work and their effect on the resulting guidance are discussed. The basic international principles recommended can be expressed in the following compressed form: (1) serious deterministic effects should be avoided by intervention, (2) each protective measure should be justified, i.e. do more good than harm, (3) the level at which the protective measures are to be introduced should be optimized, i.e. do most good, and (4) each protective measure should be optimized separately and independent of all other countermeasures. It is of great importance that decision makers inform the public of all aspects of their decisions in order to make the decisions transparent, especially when the interventions chosen are mainly for political or social reason rather than health protection grounds. Otherwise the public may be misled and the radiological protection community will be mistrusted. 17 refs., 6 tabs.