The Battle of the Dardanelles is one of the key episodes of World War I on the Ottoman front between the British, the French, the Australians and New Zealanders on the one side, and the Ottoman army under German command on the other. Immediately after the Great War, the former belligerents engaged in another war, which protracts up until the present day: allegations of violations of the rules of war are mutually addressed, in order to become a salient element of political propaganda. Through the analysis of the major controversial issues (use of dum-dum bullets and asphyxiating gases, attacks on non-military objects and sites, treatment of prisoners of war) and the study of various sources (official documents, correspondence and reports issued by belligerent forces, memoirs of Dardanelles' veterans, ICRC reports) this article scrutinizes two crucial questions. Were the rules of war taken seriously on the battlefield? Was the law instrumentalized by the belligerents?