This paper examines the various legal constraints upon action by relief workers when faced with violations of human rights or of humanitarian law. The unique status of the International Committee of the Red Cross (ICRC) and its delegates is explained and contrasted with the position of relief organizations and their personnel under the Geneva Conventions 1949 and their Additional Protocol I 1977. Proposals are made for the establishment of guidelines for action by relief workers when confronted with atrocities and for the training of relief workers in the relevant laws and procedures.