This study investigates the extent to which the factors included in the dynamic model of educational effectiveness are associated with student achievement gains in six different European countries. At classroom level, the dynamic model refers to eight factors relating to teacher behavior in the classroom: orientation, structuring, questioning, teaching-modeling, application, management of time, teacher role in making classroom a learning environment, and classroom assessment. This paper presents results concerned with the impact of the teacher factors on student achievement. In each participating country (i.e., Belgium/Flanders, Cyprus, Germany, Greece, Ireland, and Slovenia), a sample of at least 50 primary schools (n?=?334) was drawn. Written tests in mathematics and science were administered to all grade 4 students (n?=?10,742) at the beginning and at the end of the school year 2010-2011. Students were also asked to complete a questionnaire concerning the eight teacher factors of the dynamic model. Structural equation modeling techniques were used to test the construct validity of the student questionnaire. Both across and within country analyses revealed that student ratings are reliable and valid for measuring the functioning of the teacher factors included in the dynamic model. Multilevel analyses revealed that teacher factors are associated with student achievement gains in mathematics and science. Implications for the development of educational effectiveness research and for improving quality of teaching are drawn.