He was 31 years old, and a lieutenant when the following deed took place for which he was awarded the VC:

On 30 October 1917 at the Meetscheele Spur, near Passchendaele, Belgium, Lieutenant McKenzie was "in charge of a section of four machine guns accompanying the infantry in an attack. Seeing that all the officers and most of the NCOs of an infantry company had become casualties and that the men were hesitating before a nest of enemy machine-guns, he handed over his command to an NCO, rallied the infantry, organised an attack and captured the strong-point". As machine-gun fire from a pill-box nearby inflicted further casualties on the advancing Canadians, McKenzie conducted a brief reconnaissance of the position and after placing down troops in fire support positions, he led a frontal attack on the position. The pill-box was subsequently captured but McKenzie was killed in the effort.

Hugh McKenzie also received the French Croix de Guerre for his actions. He has no known grave and is commemorated on the Menin Gate war memorial in Ypres, Belgium.

When the award of his Victoria Cross was announced in the London Gazette on 12 February 1918, his surname was misspelled as "Mackenzie." He is also commemorated by a plaque at the Rosebank Primary School, in Dundee, Scotland, which he attended as a child.