Background Lung cancer is substantially attributable to smoking, but detailed related estimates on smoking-attributable expenditure (SAE) in China are not available yet, which could inform tobacco control and cancer prevention initiatives.

Methods A prevalence-based approach was adopted to estimate the total SAE, including direct expenditure (medical and non-medical) and indirect cost (disability and premature death). Detailed per-patient data on direct expenditure and work-loss days were acquired from a unique multicentre survey in China. Other parameters were from literatures and official reports.

Results The total estimated SAE of lung cancer was US$5249 million in China in 2015 (0.05 % of gross domestic product for China). The estimated direct SAE was US$1937 million (36.9 % of the total SAE), accounting for 0.29 % of total healthcare expenditure for China. The medical and non-medical direct expenditures were US$1749 million and US$188 million, respectively. The estimated indirect cost was US$3312 million (63.1 % of the total SAE), including US$377 million due to disability and US$2935 million due to premature death. The SAE increased with age, peaking at 60–64 years (US$1004 million), and was higher among men, in urban areas and in eastern China. If smoking prevalence was reduced to 20%, as is the goal of Healthy China 2030, the total SAE would be decreased by 4.9 %.

Conclusions Smoking-attributable economic burden caused by lung cancer was substantial in China in 2015, and will continue increasing given current trends in lung cancer. However, future economic burden can be prevented with implementation of effective tobacco control and other interventions.