Introduction: Burns are one of the most common types of wounds. Severe burns can cause morbidity and a relatively high degree of disability. The impact of obesity on the burn population has produced mixed results in several studies. Obese patients also have an increased risk of increasing the length of hospital stay. Aim: This study was to determine the comparison of scald burn patient outcomes based on body mass index. Method: This research is a comparative-analytic study with a retrospective cohort study design, using secondary data from the medical records of burn patients at RSUP H. Adam Malik from 2016 to 2018. The total sample obtained was 81 people. Then the mean comparison test was carried out for more than two groups and the data distribution was normal so that the One Way Anova test was carried out. Result: Patients with normal BMI the results were 12.7 + 2.0, while the results in patients with overweight categories were 19.0 + 1.9, in the obese 1 category group the results were 22.5 + 1.8, in the obese 2 group the results were 27.6 + 1.8, and in the category group Obese 3 results obtained 34.3 + 1.6, the significance of the One Way Anova test is p-value <0.001. While the BMI analysis of mortality rates was carried out by using the chi-square test, with 0% results in the normal BMI category, 0% in the overweight category group, while in the obese 1 category group 13.3%, 23.0% results in the patient group. obese category 2, and 66.7% of patients in the obese category 3 group with a significant p-value of <0.001 in the chi-square test of this study. Conclusion: The higher the body mass index group level, the higher the length of hospital stay and the mortality rate for patients.