Background: The social gradient of Non-Communicable Diseases (NCD) has been widely studied. However, little has been done to understand health inequality across populations within a country, such as between municipalities. We use Bolivian municipal data to analyze the social inequality in the incidence of NCDs and identify social determinants that contribute to this inequality.Methods: First, we estimate curves and concentration indices (CI) of NCDs incidence, measuring the municipal socioeconomic status by the index of Unsatisfied Basic Needs. We rank municipalities from the poorest to the least poor. Then, we decompose the CI into some of its main social determinants using Wagstaff decomposition analysis. The information related to the incidence of NCDs is from the National Health Management Information System (HMI). Incidence rates are standardized by municipal demographics and availability of health services to control for these confounders during the analysis. Socioeconomic data at the municipal level for 2018 comes from the National Institute of Statistics, Sustainable Development Solutions Network - Bolivia, and projections.Results: The CI for NCDs incidence is 0.20 (95% confidence interval: [0.06,0.34]), which shows that the population with NCDs concentrates in relatively less poor municipalities. Consistent with global patterns, hypertension and diabetes have the highest incidence and inequality. We separate the contribution of five social determinants to the inequality of hypertension and diabetes: (1) urbanization rate, (2) education, (3) indigenous people, (4) sanitation, and (5) the percentage of women with anemia. We find that the most relevant are the urbanization rate and education. The rate of urbanization contributes positively to inequality, while years of education contribute negatively. Conclusion: There is an unequal distribution of NCDs that disadvantages municipalities of higher socioeconomic status. One of the main determinants is the urbanization rate. These results are consistent with the hypothesis that, in developing countries, rapid and unplanned urbanization tends to change people’s way of life, potentially leading them to develop behavioral risk factors that contribute to the incidence of NCDs. Thus, policies on healthy urban environments and health education focused on municipalities with high incidence could help to curb the increase of NCDs in Bolivia.