At the departure of the Aldershot staff with Sir Redvers Buller in the conflict with the Boers in 1899, he acted as chief staff-officer at the camp at Aldershot, and was entrusted with the duties of mobilization. In December, 1899, when the sixth division of the South-African field force was mobilized, Goldsmid was selected as chief staff-officer to General Thomas Kelly-Kenny with the grade of assistant adjutant-general, and in that capacity was present at the battle of Paardeberg. During the earlier stages of the war he was commandant of the Orange River, Herbert, and Hay districts, 1900. After his service in South Africa, he was placed on half-pay in July 1901.