Emotion dysregulation is increasingly implicated as a transdiagnostic risk factor in the etiology of mental health problems. This project aimed to explore the links between emotion regulation, negative parenting and student-teacher relationships using longitudinal and ecologically valid data. A sample of n = 209 young people enrolled in the 'Decades-to-Minutes' (D2M) study, based in Zurich, Switzerland, provided data from the ages of 7-20 via parent- and self-report questionnaires and ecological momentary assessment. Data were analyzed using Dynamic Structural Equation Modeling (DSEM). Worse student-teacher relationships predicted increased negative affectivity and emotional lability. Negative parenting practices predicted emotional lability only via their impact on student-teacher relationships. The findings point to worse student-teacher relationships as risk factors in the socioemotional development of children and young people.