OBJECTIVE: To analyse smoking behaviour in patients suffering from non-small cell lung cancer (NSCLC), chronic obstructive pulmonary disease (COPD) and pulmonary TB (PTB).METHODS: The study population comprised 421 inpatients newly diagnosed with NSCLC, COPD and PTB at the First Affiliated Hospital of Chongqing Medical University, Chongqing, China, and 362 healthy individuals (controls) recruited from September 2016 to March 2017. All participants were current smokers. After enrolment, the subjects were invited to participate in face-to-face interviews to complete the self-designed questionnaire. A follow-up survey was performed 2 years later.RESULTS: Two years after being diagnosed, patients with NSCLC, COPD and PTB had smoking cessation rates of respectively 76.8%, 62.8% and 63.7%. The cessation rate was only 10.2% in the control group (P < 0.01). The difficulty of smoking cessation after diagnosis in patients with the three diseases was significantly decreased (P < 0.01).CONCLUSION: The smoking cessation rate among participants suffering from NSCLC, COPD and PTB increased after diagnosis compared with that before diagnosis, and was significantly higher than the control group of healthy individuals.