Abstract: Objective: This study estimated the population attributable fractions, preventable deaths, and indirect economic costs from major non-communicable diseases (NCDs) and all causes associated with excessive sitting time in Argentina in 2019. Methods: Population attributable fractions were used to calculate preventable deaths from NCDs and all causes associated with prolonged sitting time ( 6 h/d). Then, the human capital approach was used to quantify the present value of lifetime earnings, which was subsequently used to calculate indirect costs due to lost productivity. A Monte Carlo simulation was performed in three counterfactual scenarios to evaluate the sensitivity of the results. Results: In Argentinian men and women, respectively, approximately 11.3% (381) [10% (290)] of deaths from colon cancer, 4.4% (250) from breast cancer (women only), 4.6% (588) [4.4% (402)] from coronary heart disease, 30.5% (1390) [27% (1047)] from diabetes, and 14.9% (24,686) [13.7% (21,418)] from all causes could have been avoided annually by eliminating excessive sitting time. The indirect economic Q2 costs of excessive sitting time reached 0.025% (0.019%e0.032%) and 0.37% (0.25e0.58%) of GDP for major NCDs and all causes, respectively. High levels of heterogeneity were found at the regional level. Conclusion: Prolonged sitting time generates substantial societal costs. Public policies aimed at reducing excessive sedentary behavior in the overall population, especially in the most affected regions, would represent considerable savings for society as a whole. Such initiatives should address the complex and multifactorial causes of sedentary behavior, the clear gender and age differences in this behavior, and the factors underlying these differences.