This study examined the amount and quality of educational dialogue in relation to student math performance in Grade 2. Domains of teacher occupational stress were considered predicting variables for dialogue and math performance. Video-recorded lessons (N = 151) of 50 teachers were analysed in terms of dialogic episodes to determine the amount (length and number of episodes) and quality (four patterns) of dialogue. Multilevel modelling showed that the amount of educational dialogue associated positively with student math performance. In addition, teacher cynicism was related to math performance via the amount of educational dialogue. Regarding dialogue quality, moderate-quality dialogue linked positively with student math performance, but no indirect associations were found when considering teacher cynicism. The findings provide important new knowledge by investigating the effect of educational dialogue on young students' achievement and by mapping indirect associations between teacher occupational stress, dialogue, and student math performance.