BACKGROUND: Nonmalignant upper gastrointestinal diseases, including peptic ulcer disease (PUD), gastritis and duodenitis (GD), and gastroesophageal reflux disease (GERD), significantly challenge global healthcare. These conditions not only impact patient health but also highlight socioeconomic development issues and healthcare system accessibility and efficiency. Utilizing the Global Burden of Disease database, this study aims to comprehensively assess the global burden of PUD, GD, and GERD, examining their association with the sociodemographic index (SDI). METHODS: Employing data from the Global Burden of Disease 2019 database, this study analyzed the disability-adjusted life years for PUD, GD, and GERD. We integrated the SDI with the inequality slope index and concentration index for an international health inequality analysis, assessing disparities in the burden of these nonmalignant upper gastrointestinal diseases. Decomposition analysis was conducted to determine the effects of population growth, aging, and epidemiological change on disease burden. Frontier analysis was performed to identify potential improvement areas and disparities among countries by development status. Disease time trends were depicted using a Joinpoint regression model, and the Bayesian age-period-cohort model projected the disease burden up to 2030. RESULTS: Between 1990 and 2019, the age-standardized disability-adjusted life years rates for nonmalignant upper gastrointestinal diseases declined. However, global geographic heterogeneity remained evident and closely linked to the SDI. Notably, low-SDI countries experienced higher disease burdens. Population growth and aging emerged as principal contributors to the increasing disease burden. Despite development levels, many countries have considerable potential for reducing the burden of these diseases. Furthermore, significant variations in the time trends of nonmalignant upper gastrointestinal diseases were observed among countries and regions with different SDI levels, a pattern expected to continue through 2030. CONCLUSION: Nonmalignant upper gastrointestinal diseases demonstrate notable heterogeneity across age, sex, and geography, with the disparities most marked in underdeveloped regions or countries. Consequently, it is imperative to focus research on policy development and to enact prevention and treatment strategies tailored to high-risk groups. This targeted approach is essential for effectively mitigating the disease burden.