The purpose of this study was to improve the job performance of teachers by measuring the factors affecting the performance of teachers at higher secondary level. Main objectives of the study were to measure and summarize the perceptions of principals, teachers themselves and students about the factors that influence teachers’ performance, to compare teachers’ performance on each factor in the light of perceptions of principals, teachers themselves and students, to determine the rating of principals, teachers themselves and their students on each factor, to discover the level of presence of each factor on teachers’ job performance in the light of perceptions of principals, teachers themselves and students and to recommend improvement of the existing situation. The study was descriptive in nature. All the principals, teachers and students at higher secondary level in Punjab constituted the population of the study. The principal, five teachers and ten students were included in the sample from each institution, thus the sample consisted of 1920 individuals i.e. 120 principals, 600 teachers and 1200 students. Three types of closed ended questionnaires on five point rating scale were prepared separately for principals, teachers and students. The data obtained were tabulated, analyzed and interpreted by using statistical techniques as, mean, standard deviation, average rating and analysis of variance (ANOVA). The main conclusions of the study were that the factor of subject mastery was perceived by the principals, teachers themselves and students to be at the highest level among the four factors of teachers’ job performance. The factor of attitude toward students was viewed to be at the lowest level among the four factors of teachers’ job performance. Teaching methodology and teachers’ personal characteristics were factors considered to be present in teachers’ performance at intermediary level. xiiiThe average rating of teachers was the highest whereas that of students was the lowest on all the four factors, namely the attitude toward students, subject mastery, teaching methodology and personal characteristics of teachers’ job performance. The rating of the principals was at intermediary level. There was no real difference among the views of principals, teachers themselves and students about teachers’ performance on the factors of attitude toward students, subject mastery and teaching methodology. However, the views of principals, teachers themselves and students were found different on the factor of teachers’ personal characteristics. On the basis of analysis of the study, it was recommended that though the factor of teachers’ job performance was found on the highest level in the present study, yet teachers should continue their attention and improve their command on the content through self study and by attending in service refresher courses. The attitude toward students, as a factor of teachers’ job performance as analyzed was perceived at the lowest. So teachers need to improve their approach toward the students in order to improve their performance. Teachers are required to continually improve their teaching methodology by consulting internet media, new informatory literature to bring innovation in their teaching methodology. The factor of personal characteristics of teachers’ job performance was given the third position among the four factors, thus teachers should give specific attention toward this factor by improving their personality characteristics such as use of easily understandable language, removal of potential blocks to communication, use of key vocabulary, use of different channels of communication to facilitate the students and xivalso speak clearly and vary the tone pitch and inflection of the voice to all areas of the classroom. In the light of above mentioned conclusions, it can be suggested that if teachers improve their performance on the four factors attitude toward students, subject mastery, teaching methodology and personal characteristics, a significant improvement can be made in teachers’ job performance. Due to few research studies conducted in Pakistan, there is a need to conduct more studies in this area in the future. The present study was conducted in the province of Punjab, the future researchers may expand it to other provinces of the country in order to measure the factors affecting the teachers’ job performance at national level. The present study was delimited to four factors only as attitude toward students, subject mastery, teaching methodology and personal characteristics, whereas the literature indicates a number of other factors such as the classroom environment, general mental ability, personality, relations with students, preparation and planning, effectiveness in presenting subject matters, relations with other staff, self improvement, relations with parents and community, poise, intellect, teaching techniques, interaction with students, motivational skills and fairness in grading etc.