Objective: : Low back pain (LBP) is a global health problem that affects the productivity of the patients. Several factors such as individual, occupational, and psychosocial factors increase the risk of LBP. However, only a few studies investigated those factors, especially in middle adulthood in Indonesia. Indonesia is a country with a young population that has been rapidly developing in recent years. This study was conducted to find out the factors associated with LBP in middle adulthood. Methods: : This study is a cross-sectional observational analytic study using a convenience sampling method with a total sample of 3005 respondents. Data were collected using a questionnaire which was then analyzed using the chi-square test, Kolmogorovsmirnov, Spearman’s Rank, and logistic regression test. Results: : From the result of this study, it was found that the 12-month prevalence of LBP in middle-aged adults was 44,29%. Female (odds ratio [OR], 1.3; 95% confidence interval [Cl], 1.098–1.545; p=0.002), lack of physical exercises (OR, 0.87; 95% Cl, 0.794–0.959; p=0.005), high body mass index (OR, 1.09; 95% Cl, 1.009–1.187; p=0.002), stress level (OR, 1.26; 95% Cl, 1.088–1.458; p=0.002), and years of work experience (OR, 1.1; 95% Cl, 1.001–1.225; p=0.047) were determined as risk factors that significantly associated with LBP. Conclusion : LBP is quite common among middle-aged adults in Indonesia. Female gender, higher body mass index, lack of physical activity, stress level, and years of work experience were all potential risk factors for LBP in middle-aged adults. Middle-aged adults in Indonesia should be aware of LBP and avoid disabilities by identifying risk factors that may worsen LBP in the future.