Lung cancer is a preventable disease that has a poor prognosis in most patients. It has a high association with tobacco smoking. Diagnosis involves looking for new symptoms and signs, or changes in existing ones, with a heightened index of suspicion in patients who have ever smoked.This article outlines the role of the general practitioner in the diagnosis, treatment and palliative care of the patient with lung cancer.The risk of developing lung cancer increases with increasing cigarette smoking and decreases when smoking is ceased. The development or change in a 'usual' cough should alert the GP to a diagnosis of lung cancer. Any referral to a respiratory specialist must be preceded by informing the patient of the nature of the possible disease, and ensuring that the patient has a realistic understanding of the limited chance of cure. Palliation is required by most patients with the GP playing an important role. Promotion of smoking cessation is the only real strategy available to doctors to reduce morbidity from this disease.