We study which students’ characteristics teachers take into consideration when grading German pupils in lower secondary schools, analysing gender mismatches between teachers’ grading and test scores. We assess gender gaps along the distribution of grades across two subjects considering an extensive set of measures of students’ personality traits, school-related attitudes, and behaviors. Relying on the German National Educational Panel Study – Starting Cohort 3, we focus on 7th grade students in 2012. Results from multilevel regression models indicate that girls with the same subject-specific competences as boys obtain on average higher grades in language. The KHB decomposition method suggests that girls’ advantages in grades can be explained mainly by their higher levels of conscientiousness and subject-specific interest.