Scott-Moncrieff joined the Royal Engineers in 1873 and served in Afghanistan from 1878–1880. He was an Instructor at the School of Military Engineering from 1893–1898. He was Commander of the Royal Engineers, China Expeditionary Force 1900–1901, taking part in the relief of Peking and the Waziristan expedition on the North West Frontier, India 1901–1902.