Studies investigating changes in the general population over time concerning adolescent self-reported Quality of life (QoL) are sparse. The aim of this study is to investigate stability and change over more than a decade in self-reported QoL, emotional problems, and negative stressful life-events among students. Three large cross-sectional samples (N = 1032, 4744 and 3826) of 13–17-year-old adolescents attending public school in the Norwegian County of Trøndelag provide data, one from 2017 to 2019 and two from 11 and 13 years earlier. We analyzed linear and binary linear regression adjusted for age. We found few indications of large changes in overall QoL. The exception was a 50% increase in reported emotional problems in both girls and boys. Girls also reported an increase of sexually uncomfortable/abusive acts from peers from 3.7 to 7.0%. The observed changes must be addressed through public health interventions targeting school as an important arena.