Experts carried out a random controlled trial on more than 12,000 people in Scotland who were at high risk of developing the disease.
They found people who took the test were more likely to be diagnosed with cancer at an early stage.
Chief investigator, Prof Frank Sullivan, said the findings could have “globally significant implications”.
Lung cancer is the most common cancer that kills in Scotland, and is attributed to a quarter of the country’s cancer-related deaths.
About 85% of patients in the UK are left undiagnosed until the disease has spread to other parts of the body.
However the Early Detection of Cancer of the Lung Scotland trial found the test could detect the illness four years or more before standard clinical diagnosis.
How did the trial work?
In what is believed to be the largest trial of its kind in the world, 12,209 patients from Glasgow, Lanarkshire and Tayside were recruited to take part.
They were all adults aged 50-75 who were smokers or former smokers.
Of those who received the EarlyCDT lung test and went on to develop lung cancer, 41.1% were diagnosed at an early stage (stage 1 and 2) .
Meanwhile about a quarter (26.8%) of the control group who received standard care were diagnosed early.