Student ratings are widely used to assess teaching quality in primary and secondary education. This necessitates a thorough examination their validity and reliability in such contexts. To this end, we present validity evidence for using student ratings of teaching quality based on their factorial structure, comparability across grades and subjects, and relation to achievement. Based on data from the 2019 Trends in Mathematics and Science Study (TIMSS) and its national extensions in Norway (N = 3951 5th graders and N = 4575 9th graders), we could confirm a theoretically assumed three-dimensional factor structure (i.e., classroom management, cognitive activation, and supportive climate). Moreover, classroom management and supportive climate were more comparable across grades and subjects then cognitive activation. Finally, classroom management was associated with achievement across all groups, whereas other dimensions showed mixed results, especially across grades. Overall, the findings indicate that students, especially in Grade 9, can provide a valid assessment of teaching quality.