This study aimed to explore the experiences of District management and school staff regarding newly introduced teacher performance assessment system in Government schools of Gilgit- Balistan. The study was conducted in two government schools of the district using qualitative case study approach. Semi-structured interviews, field notes and document analysis were sources of data collection. The study involved seven research participants, a district education officer, two head teachers and four teachers from Gilgit-BaItistan. The study has generated some interesting findings related to their experience. In Government context, there were some concerns and issues in relation to quality teaching, students' learning and drawbacks in the existing performance appraisal tool- Annual Confidential Report, which led the district management to develop and implement a system that was more professional development oriented. It aimed to improve teachers' teaching practices, identifying their needs for the provision of support and accountability. New assessment system was understood as a systematic process of collecting information about teachers' performance for feedback and development. The teachers had positive attitudes towards the new system as it helped them to enhance their content knowledge, planning skills, reflective practices and change their traditional belief of teaching. Most importantly, the systematic process played crucial role in changing the attitude of the teachers towards teaching which contributed to quality teaching and students' achievement. However, teachers had some concerns about unannounced observations and nature of feedback while head teachers experienced less support from the senior management for professional support and monitoring. The District management dealing with large number of schools experienced lack of capacity as a challenge in its effective implementation. The data indicated that collaborative efforts of some key representatives in designing and pilot testing for the feedback before its implementation could be more effective. This study is significant for practitioners to reflect upon their practices and refine the tool to maximize the positive aspects and minimize the shortcomings to make it effective and purposeful.