Lung cancer is the most common cause of cancer-related death in the UK. Despite aggressive primary prevention measures and improved medical care, the 5-year survival rate is less than 10% for patients in the UK who present with symptoms. The possibility of CT screening for lung cancer provides some hope of reducing mortality. However, the case for screening remains unproven. This article explores the issues surrounding lung cancer screening in the context of historical studies, trials in progress and tentative plans for a UK CT lung cancer screening trial.