[5] During the war Abercrombie served in the Otago Infantry Regiment (OIR), enlisting as a private in December 1914.
[9] Late the following month he took part in the landing at Anzac Cove, the initial stage of the Gallipoli campaign.
In early August he took part in the landing at Suvla Bay, the final attempt by the British and Empire forces to break the stalemate at Gallipoli.
He was wounded in the face on 7 August during the Battle of Chunuk Bair and was evacuated from the peninsula, first to Malta before being sent to England where he spent five months at the 2nd Western General Hospital in Manchester.
[5] Promoted to the rank of corporal, he saw action on the Western Front and was wounded again on 14 July whilst serving in the Armentières area during the early stages of the Battle of the Somme.
[12] After being released from hospital in September 1916, Abercrombie spent nine months at the New Zealand Command Depot at Codford in Wiltshire to further recuperate.
In May 1917 he was posted back to France, serving with the 3rd battalion of the OIR, during which time the New Zealand Division saw action at Messines and St.
[11][13] Promoted to the rank of second lieutenant in November,[14] Abercrombie did not rejoin his unit, instead being posted back to New Zealand, arriving at Wellington in March 1918.
[35][36][37] After nearly six years at Riverton, in early 1936 Abercrombie was transferred to the manager's job at Lower Hutt, near Wellington on New Zealand's North Island,[38][39][40] leaving Southland in March.