Problem behaviors in preschool-aged children negatively affect teacher-child relationships and children's skill development. In this clinical replication of an initial study, we implemented Teacher-Child Interaction Training (TCIT), a teacher-delivered, universal intervention designed for early childhood settings. The initial study evaluated the TCIT program in a sample of 4- to 5-year-old children, whereas the current study focused on 2- to 3-year-old children. Teacher ratings of children's behavior indicated a significant main effect for time on children's protective factor scores, but not on behavioral concerns. However, for children whose ratings fell in the below-average range at baseline, significant large effect sizes were obtained for changes over time for both protective factors and behavioral concerns. Higher levels of teacher skill change were significantly associated with overall higher protective factor scores, as well as lower behavioral concern scores for children when baseline levels of behavioral concerns were high. Results provide further support for the effectiveness of TCIT as a universal intervention designed to improve children's behaviors through targeted improvements in teachers' relationship-building skills and classroom management strategies. (author abstract)