OBJECTIVE: Nursery school teachers are exposed to psycho-emotional stress in their profession, which can lead to health problems. The aim of the study was to examine whether and to what extent increased work commitment (overcommitment, OC) affects the health of educators. METHODS: 163 nursery school teachers (age 44.5 +/- 12.4 years) were recruited for the study. OC, mental health and the risk of burnout were assessed using standardized questionnaires. ECG recordings over 24 h served as a basis for the calculation of heart rate variability (HRV). RESULTS: 121 teachers showed normal OC and 42 teachers increased OC. In nursery school teachers with elevated OC, self-reported mental health is impaired and vagal mediated HRV (RMSSD and HF) is reduced. CONCLUSION: Since the subjectively assessed mental health of nursery school teachers with elevated OC deteriorates and HRV is reduced, preventive measures must be taken to maintain the health of nursery school teachers.