###### Abstract  
Tracheal, bronchus, and lung cancer (TBLC) remains a major public health concern. Knowledge about geographic patterns and time trends in TBLC could give insights to better address this problem. This study aimed to evaluate the geographic patterns and time trends in mortality due to TBLC observed in Portugal. TBLC-related deaths and population estimates (2011-2021) were derived from the Instituto Nacional de Estatistica. Age-standardized mortality rates for people aged 50 or more (ASMR_50+) per 100,000 were obtained. Analyses were stratified by gender, geographic region, and level of urbanization. The time trends in ASMR_50+ were evaluated using joinpoint regression models, and the values for the annual percentage change (APC) and the respective 95% confidence interval (95% CI) were obtained. Differences in mortality due to TBLC between regions and levels of urbanization (2017-2021) were assessed through a standardized mortality ratio (SMR) and the respective 95% CI. In 2021, the ASMR_50+ per 100,000 inhabitants observed in mainland Portugal was 158.0 and 40.4 among men and women, respectively. According to the time-trend analysis, ASMR_50+ due to TBLC remained stable or described a downward trend among men, but there was an upward trend among women in suburban and urban regions. Observed deaths were significantly higher than the expected for men in urban areas (SMR = 125%; 95% CI: 121-128 and SMR = 118%; 95% CI: 115-122 in Norte and Lisboa, respectively), and women in Urban Norte (SMR = 125%; 95%CI: 119-131). Lower mortality than expected was observed among men living in Rural Norte and Rural Centro, as well as, among women living in all the rural areas. In suburban areas, the observed deaths were lower, higher, or as expected depending on the geographic region and gender. A notable upward trend in mortality due to TBLC among women was observed. The geographic patterns observed suggest the effects of deleterious environmental factors and smoking habits, deserving attention from policymakers. tracheal, bronchus, and lung cancer; mortality rate; time trends; geographic pattern; Portugal 202 of 53 per 100,000 inhabitants and accounting for almost 10% of the global cancer burden [4]. At same time, the mortality rate due to TBLC was 47 per 100,000, corresponding to 15% of all cancer-related deaths reported in Portugal [5]. Nowadays, among the 40 European countries, Portugal presents the 18 th highest crude mortality rate due to TBLC [4]. Between 1955 and 2005, Portugal witnessed an increase in TBLC mortality among women, deserving particular concern [6]. A poor survival rate for patients diagnosed with TBLC has been reported in Portugal, where the cumulative survival rate of 5 years was 10.7% and 22.9% among men and women, respectively [7]. Due to the high fatality rate of TBLC, the mortality rate could be read as a mirror of the incidence rate [8]. Therefore, research on the geographical patterns of TBLC-related deaths could give insights into the differences in the incidence of this disease. Differences in TBLC incidence and mortality are due to known risk factors which vary across geographic areas or population groups. The main risk factor is tobacco [1; 2; 7; 9], followed by air pollution [2; 9] and occupational carcinogens [2; 8; 9]. The TBLC burden is higher in men than in women mainly due to differences in smoking patterns [8]. However, there has been a consistent increase in incidence rates among women, becoming nearly identical to that of men [2; 9]. Between 1988 and 2008, the prevalence of smoking observed in Portugal decreased among men but there was an upward trend in such prevalence among women [10]. Meanwhile, since 2005, Portugal has been strongly committed to tobacco control and protection of citizens against involuntary exposure to tobacco smoke [11]. The efforts of the Portuguese government in decreasing smoking prevalence would have had an impact on TBLC incidence and mortality.