A study was conducted to develop the research instrument for evaluating the Performance Appraisal System (PAS) at public higher secondary schools in Punjab. Data were collected from the three divisions total (N=900) male and female teachers of public schools using a multi-stage sampling technique. The questionnaire was founded on the factors elaborated in the Performance Evaluation Report (PER), National Professional Standards (NPS) for teachers. This scale is extended to evaluate the satisfaction of the teachers with the performance appraisal process. The factors taken from PER are classroom management, quality of teaching, motivation, teamwork, and punctuality, whereas Awareness, Satisfaction with PAS, Dissatisfaction with PAS, and Need for Improvement were added by the researchers to evaluate the PAS process. Performance Appraisal Scale for higher secondary school teachers (PAS-HSSTs) contained 57 items. The experts' opinion was sought to check for content validity, and a pilot study was performed with 300 teachers from public higher secondary schools. The reliability coefficient (Cronbach alpha) of the instrument was .866 for the pilot and .883 for final data. Structure Equation Modelling (SEM) was used for the validation of the instrument (PAS-HSSTs) using Confirmatory Factor Analysis (CFA). The factor loadings of all items used in the scale were well above the threshold value 0.35. The SEM results indicated that Fit indices for PAS resulted in an acceptable model fit.