This study aimed to provide the administrators and teachers with insights, along with the strengths and weaknesses, of instructor evaluation via the perceptions of English instructors for school improvement. The study employed the Utilized Focused Evaluation as its framework. Data were collected through a mixed method design, including a questionnaire and interviews. The results revealed that the instructor evaluation process has a positive effect on teacher professional development and school improvement. The findings indicate that to make instructor evaluation more useful, improvements should be made to classroom observation procedures and more time should be allocated for teacher professional development by the administrators.