World War I historiography focuses on the introduction of chemical weapons to European battlefields, mainly the Western Front, but ignores their use during the Palestine Campaign. In 1917 the (British) Egyptian Expeditionary Force fired chemical-filled artillery shells against Ottoman forces. During the Second Battle of Gaza (April 1917), the chemical bombardment was unsuccessful in supporting the infantry assault. In the Third Battle of Gaza (October–November 1917), it was much more effective in its diversionary role of drawing Ottoman attention away from the main thrust toward Beersheba. This article examines the chemical operations and the Ottoman response, analyses the outcome, and suggests explanations for the historiographical disregard of these events.