The study on impact of teacher performance appraisal (TPA) on appraisers aimed at exploring the impact of appraisal on the performance of the appraisers, which has mostly been a neglected area of research in educational settings. The reasons of selecting this topic for research were my past personal experiences as an appraiser and the issues related to appraisal in my organization. I reviewed the literature which shows the impact of appraisal on teachers and students, but very little has been said from the appraiser's point of view. This study has been conducted in Bright Future School (BFS, pseudonym) one of the private secondary schools for boys in Karachi. The school has a unique model of TPA, which I call the three- phased model' of appraisal. There are three approaches; one approach is only for the teachers who are in their probationary period, the second serves formative purposes of teacher evaluations, and the third is appraisal for performance review of teachers done at the end of each year, and it serves the summative evaluation purposes. Qualitative case study was chosen as a method for this study, as it was very contextual. Four appraisers including the principal of the school and a teacher were taken as participants. The data were collected through interviews, documents analysis, and general observation of the school. The findings of the study revealed that TPA has both positive and negative impacts on appraisers. It shows appraisal as double loop learning for appraisers. It is not only a kind of benchmark for them, but they also enhance their job- related knowledge and skills like teaching strategies, planning, classroom management, communication, and evaluation. It also shows that appraisal has brought a positive change in the appraisers' attitude towards appraisal and the appraisers. Apart from the positive changes, the findings also show one negative aspect of appraisal, which is its rigidity. It limits the creativity of the teachers and makes them very dependent, when it only focuses the targets set by the appraisers. In this case, the relation between teachers and appraisers becomes super-ordinate and subordinate, which is a hurdle in the way of creating a friendly learning environment. The findings show that the TPA model of BFS is a relatively successful model, which links the individual goals with organizational goals, and ultimately leads towards the goals of providing quality education to children. It also serves simultaneously both the developmental and