After working as a law clerk for only a few months, the outbreak of the Second World War led Wilmot to join the Australian Broadcasting Corporation. He was sent to the Middle East in 1940 and reported from North Africa, Greece and Syria; he was in Tobruk during the siege of 1941. When Japan entered the war, Wilmot returned to Australia, then went out to cover the war in the Pacific. He reported from Papua during the Japanese invasion in 1942, including the Kokoda Track campaign, where he walked up to the forward area, around Abuari and Isurava, with fellow war correspondent Osmar White and cinematographer Damien Parer. Wilmot regarded General Sir Thomas Blamey as incompetent and protested at his sacking of Lieutenant General Sydney Rowell.