BackgroundUnderstanding disparities in the burden of cancer attributable to smoking is crucial to inform and improve tobacco control measures. In this report, we estimate the population attributable fraction (PAF) of cancers deaths attributable to smoking at the national and provincial levels in China.MethodsUsing cancer mortality data from 978 counties, smoking data from a nationwide survey and relative risks from a prospective study of 0.5 million adults in China, we calculated the absolute (non-standardised) and standardised numbers and proportions of cancer deaths among adults 30 years and older attributable to active and second-hand smoking in 2014 across all 31 provinces in Mainland China.ResultsThe estimated number of cancer deaths attributable to smoking in China in 2014 was 342 854 among men and 40 313 among women, of which second-hand smoking accounted for 1.8% and 50.0%, respectively. Among men, the absolute PAF in China was 23.8%, ranging from 14.6% in Xinjiang to 26.8% in Tianjin; the overall standardised PAF was 22.2%, ranging from 15.7% in Xinjiang to 26.0% in Guizhou. Among women, the overall absolute and standardised PAFs were 4.8% and 4.0%, ranging from 1.8% and 1.6% in Jiangxi to 14.9% and 9.6% in Heilongjiang, respectively. Overall, provinces with the highest standardised PAFs among men were located in Southwest China and among women in the Northeast.ConclusionsComprehensive smoke-free policies in China should expand to all provinces, notably those with a higher burden of cancer attributable to smoking, instead of being mostly limited to Beijing and some other metropolitan areas.