After Salmond graduated from Sandhurst with a commission as a second lieutenant on 8 January 1901, he was transferred to the King's Own Royal Lancaster Regiment on 9 March 1901. He sailed for South Africa to join his unit, which was engaged in the latter part of the Second Boer War. In 1902 he applied for a secondment to the West African Frontier Force but was turned down on the grounds that he was too young: he re-applied the following year and was accepted on 14 November 1903. He was immediately seconded to the colonial service and then promoted to lieutenant on 5 April 1904. Salmond's time in Africa was cut short as he was pronounced medically unfit and returned to England in November 1906. He was promoted to captain on 26 June 1910.