A wide range of reforms to improve the teaching capacities of pre-service and in-service teachers have been carried out in Kosovo. In assessing the success of these previous interventions, large-scale assessment data is invaluable. In 2019, 4754 students from 145 schools participated in the TIMSS assessment. Results reveal that student's performance, in mathematics and science, is significantly higher when teachers are clear in their instructions, satisfied with their job, and have more teaching experience. Teacher qualifications also impact achievement, with students performing higher when the teacher only has a secondary education without a bachelor's degree. Students' higher readiness for instruction, preferences for the subjects, and confidence in their abilities are linked to higher literacy levels. Finally, TIMSS data of the 2019 study also raise questions regarding the type of homework assigned to students, the importance of experience over qualifications, and the academization of teacher preparation programs that may hinder practice.