Increasingly, preschools are integrating trauma-informed interventions, which often include components of training, to improve practices and promote the well-being of children who have experienced trauma. Similar interventions have been linked to positive outcomes for older children; however, there is limited research that examines whether or how training on trauma specifically contributes to child and staff well-being within early childhood settings such as preschools. The current study examines the relationship between trauma-informed training content, trauma-informed attitudes, and stress in a sample of 111 preschool staff (49% lead teachers, 20% assistant teachers, and 27% other staff such as administrators and classroom aides). This study examined the unique influence of training related to trauma-informed skills (e.g., screening for trauma, responding to challenging trauma-related behaviors) and trauma-informed self-reflection (e.g., the impact of a child's trauma on staff) on trauma-related attitudes and stress (including general stress and child-related stress) in a sample of teachers and staff with prior training on trauma-informed knowledge (e.g., definitions of trauma). Compared to those with only knowledge training, teachers and staff with self-reflection ([beta] = 0.22, SE = 0.09, p = 0.014) and self + skills training ([beta] = 0.50, SE = 0.13, p < 0.001) had stronger trauma-informed attitudes than those with only knowledge training. Direct pathways from training content and trauma-informed attitudes to general stress were not significant. Pathway from trauma-informed attitudes to child-related stress ([beta] = -0.51, SE = 0.12, p [less than or equal to] 0.001) and the indirect pathway from self-reflection training ([beta] = -0.11, p = 0.015) self + skill training ([beta] = -0.25, p < 0.001) to child-related stress through trauma-informed attitudes were significant. The findings of this study suggest that all trauma-informed training is not equal; training that focuses on self-reflection, such as the role of vicarious trauma, may be particularly important as part of a trauma-informed school approach. Trauma-informed attitudes are also an important mechanism through which trauma-informed interventions may influence staff well-being in preschool settings.