This study examines the effects of teachers. and students. features on student's science and mathematics performance employing two level hierarchical linear models using data from TIMSS 2011 conducted with Turkish 8th graders and their science and math teachers. The results of the research showed a significant mutual impact on science and math scores due to student's confidence with lessons and teacher's career satisfaction. The study also revealed a relationship between students' performance, students' perception of science and science teachers' confidence related to their expertise. The impacts of mentioned variables were discussed and implications for further research were provided.