Teachers in preschools and schools have a central role in detecting children at risk of maltreatment. The aim of this study was to provide a longitudinal understanding of teachers' temporary and prolonged concerns for children's home situations (CCHS), from preschool (age 3-5 years) to year 1-3 of elementary school (age 8-10 years). Teacher- and parent reports from an ongoing prospective longitudinal study was used (baseline n = 2,113; 5-year follow-up n = 1,829). The study applied the bio-ecological systems framework by assessing how teachers' CCHS were associated with person-, process-, and context-related factors. Both temporary and prolonged CCHS were primarily associated with teachers' concern for different aspects of the children's development, poor contact with parents and low parental SES, while school-related factors were less prominent. The longitudinal pattern indicates three risk levels and highlights the importance of the contact between teachers and parents in understanding when CCHS arises, ceases, or persists over time.