Purpose: The paper discusses the influence of instructional leadership on effective teacher teaching practices and learning outcomes. In particular, the paper examines one of the instructional leadership practices, namely teaching evaluation, and seeks to investigate the influence on the effective teacher practices and on the achievement of 6th grade primary school students studying mathematics in the Cyprus educational system. Design/methodology/approach: A quantitative research approach was deemed appropriate and employed for the purpose of the research subject, and in particular for the type of questions studied. Data were collected from 81 principals, 139 6th grade teachers and 1,553 students in the Cyprus educational system. In addition, data analysis was performed using structural equation models (SEM). Findings: The instructional leadership approach assumes that principal evaluations influence high learning outcomes. Findings demonstrated that the principal evaluation has a positive and statistically significant impact on effective teaching practices and student achievement. Originality/value: It is important to acknowledge that in the Cyprus educational leadership field the correlation among the instructional leadership, the effective teaching practices of teachers and the students achievements were not examined through the above parameters. Furthermore, the survey provided important insights into the principals, teachers, pupils and, more generally, on Cyprus's educational policy.