Background: Little data are available on health-related quality of life (HRQOL) of children in Germany at the age of school enrollment. Objective: Aim of this study was to investigate the HRQOL of children during school enrollment and to determine its predictors with special focus on environmental factors. Methods: Data from the fifth survey of the Health-Monitoring-Units (GME) conducted in Bavaria (2010/2011) were analyzed. Parent-reported data on HRQOL using the KINDL-R(evised), the Strength and Difficulties Questionnaire (SDQ), socio-demographic characteristics and characteristics of the living environment were assessed. Results: The sample included a total of 3,744 children (45.9% female; mean age: 6.0; SD=0.4). Girls had significantly higher values than boys in total HRQOL (83.7 vs. 82.4, p =0.0001) and in all KINDL-R subscales except 'psychological well-being' and 'physical well-being'. For the latter, boys had significantly higher values than girls (84.1 vs. 82.9, p=0.0103). Multiple linear regression analysis showed that parental annoyance with air or noise pollution, possibility for children to safely play outside and the time a child is outside on weekdays in the summertime were significant predictors of total HRQOL measured by the KINDL-R. Obesity was not linked to HRQOL. Children with migration background had significantly higher values in the subscales 'family' and 'friends'. Conclusions: Environmental factors are associated with HRQOL in children at the age of school enrollment but only partially of relevant use. Although they show significant associations, their explanatory power of the variability observed is rather limited.