The present study examines the quality and domains of teacher-toddler interactions and associations with structural characteristics using data from 95 German early childcare settings. The results of the confirmatory factor analysis supported a two-factor structure of interaction quality assessed by the CLASS Toddler: emotional and behavioural support (EBS) and engaged support for learning (ESL). The EBS domain showed higher quality ratings (M = 5.33, SD = 0.59) than the ESL domain (M = 3.23, SD = 0.70). Structural equation modelling was applied to estimate associations between those domains and structural characteristics within classrooms. Structural characteristics predicting interaction quality were teachers' age (for EBS), teachers' education (for ESL) and children's age composition in the classroom (for EBS and ESL). Overall, the two-factor structure of CLASS Toddler could be replicated. For high-quality interactions, teacher and classroom characteristics are crucial but need to be carefully distinguished. Beyond their limitations, these findings have implications that are discussed.