While in Egypt, the infantry brigade of the NZEF was combined with an Australian infantry brigade to form the New Zealand and Australian Division with Godley as its commander and intended for service in the Gallipoli Campaign. Hughes landed at Anzac Cove with Godley's headquarters on 25 April 1915. In June, he took command of the Canterbury Battalion when its commander, Lieutenant Colonel Charles Henry Brown, was wounded. He led the battalion during the Battle of Chunuk Bair, which took heavy casualties when it was caught in the open by a Turkish artillery barrage. In October he was medically evacuated due to dysentery. He was recognised for his service at Gallipoli with appointment as a Companion of the Order of St Michael and St George as well as being mentioned in despatches. After a period of convalescence in England he returned in New Zealand where he was eventually discharged from the NZEF because of his health. He was placed on the retirement list in 1917 with the honorary rank of colonel.