 Hacket Pain served in South Africa throughout the Second Boer War of 1899-1902.He was confirmed as a lieutenant-colonel on 17 February 1900, and served in command of the 2nd Battalion of the Worcestershire Regiment from 12 February 1900 to 31 May 1902, including as Commander of Troops at Rietfontein from October to December 1900.During the war he took part in operations in Colesberg in January and February 1900, in Lindley on 26 June, Bethlehem on 6–7 July, and Wittebergen throughout July 1900.