Abstract Introduction Tobacco use is one of largest contributors to preventable disease burden in the world. In Belgium, tobacco use is a public health concern and prominent on the policy agenda. To monitor tobacco use and understand the impact on associated outcomes, we estimated the population attributable fraction (PAF) to tobacco use in Belgium and used that to compute the attributable mortality. Methods We used comparative risk assessment to calculate PAF and attributable mortality to tobacco use. Using estimates of tobacco use from a time series based on five waves of the Belgian Health Interview Survey and relative risk estimates from the Global Burden of Disease Study 2019, we calculated PAFs for risk-outcome pairs by age and sex for the three regions of Belgium for 2019. We then used these fractions to estimate the deaths attributable to tobacco use with mortality estimates taken from the Belgian Burden of Disease Study. Results In Belgium, 9323 deaths among adults 30+ years in 2019 were attributable to tobacco use (PAF=13%). Tobacco-attributable deaths were highest in the Wallonia (PAF=16%, n = 3786) followed by the Brussels-Capital region (PAF=15%, n = 894) and Flanders (PAF=11%, n = 4642). Almost three times as many attributable deaths occurred in men as women (19%, n = 6803 vs PAF=7%, n = 2519, respectively). Almost half attributable deaths occurred in people under 70 (n = 4469). The majority of tobacco-related deaths were due to cancer of the trachea, bronchus and lung (PAF=50%, n = 3671) followed by chronic obstructive pulmonary disease (PAF=29%, n = 1580), and ischemic heart disease (PAF=7% n = 673). Conclusions Tobacco use is a major contributor to mortality in Belgium. The majority of deaths attributable to tobacco use are considered premature. Tobacco prevention and control should remain high on the public health agenda. Key messages • Tobacco use contributed to 13% of deaths in tobacco associated outcomes in Belgium among adults in 2019. • Tobacco control and prevention should remain high on ...