Introduction: Limited insight exists into the weight development in children with obesity not receiving obesity treatment., Methods: This cohort study included 467 Danish children aged 5-10 years with obesity (iso-BMI >30 kg/m 2 ) not receiving treatment. Data from mandatory health check-ups on school-children's height and weight (converted to BMI z-scores) were merged with the Danish National Registries. A multivariable logistic regression weighted for the duration of follow-up was used to estimate odds ratios (OR) for normalization of BMI (iso-BMI 18.5-25 kg/m 2 ) and obesity remission (iso-BMI 18.5-30 kg/m 2 )., Results: During a median follow-up of more than 6 years, 7.9% of the children normalized their BMI, while 45.4% obtained obesity remission. BMI z-score at inclusion acted as a strong inverse predictor for normalizing BMI (OR 0.14 per one-unit SD, CI: 0.03-0.53) and for obesity remission (OR 0.17 per one-unit SD, CI: 0.08-0.37). No other significant predictors were observed in the weighted multivariable models., Conclusion: Higher BMI z-scores inversely predict normalizing BMI and achieving obesity remission in untreated children. Given that many children naturally achieve obesity remission or weight normalization, resources should focus on understanding barriers of obesity maintenance and to develop effective strategies for those who do not experience improvement., (© 2025 The Author(s). Pediatric Obesity published by John Wiley & Sons Ltd on behalf of World Obesity Federation.)