The history of the rise, progress and development of advanced countries shows that they have given due consideration and importance to higher education and all their progress owes a lot to the advancement and priority given to higher education. Higher education plays leadership role in all aspects of life. By providing the quality education we can produce quality products. “Behaviour” is defined as the action or activities of an organism that is anything that an organism does, including physical action, internal physiological and emotional processes and implicit mental activity. The focus on behaviour is important in the teaching process for no one has complete control over his feelings or his personality. He does have control, however, over most of his actions and it is those actions and the decisions which generate them that contribute to successful teaching. Teaching can in fact, be defined as conscious behaviour that makes learning more probable and more efficient than it would have been without that behaviour. Teaching behaviour can range from a simple smile or pat that encourages the learner to a superbly designed, programmed presentation of a complex process that results in predictable, efficient and effective learning. Teacher behaviour and learner behaviour, it is obvious that a complex interaction occurs in teaching. The decisions and actions of a teacher affect the learning process. The teacher’s observation of the learner or previous knowledge about him affects the teaching process. The major purpose of the study was to investigate the impact of teacher’s behaviour on the academic achievement of the university students in Pakistan. The main objectives of the study were (i) to highlight the present status of universities in Pakistan, (ii) to investigate the behaviour of the university teachers in Pakistan (iii) to examine the academic achievement of the university students as a result of teacher’s behaviour (iv) to highlight the causes which affect academic achievement of the university students (v) to sort out the relationship between the teacher’s behaviour and academic achievement (vi) to recommend strategies for the improvement of teachers behaviour. All the working university teachers along with the students of universities were the population of this study. A random sampling technique was used for selection of the sample. Fifteen Public universities were included in the sample, further twenty-five teachers and hundred students form each university were also randomly selected as the sample of the study. Two questionnaires, one for university teachers and other for university students were developed for the collection of data. Further information regarding present status of universities in Pakistan were collected from Higher Education Commission website. Collected data were tabulated analyzed and interpreted in the light of objectives of the study by applying statistical tools of chi-square and Pearson’s Product – Moment coefficient of correlation(r). The level of significance was 0.05. Main conclusions of the study were, expansion of the universities was financed properly; highly qualified teachers ratio was very low. Teachers used different motivational techniques. Teachers guided students properly by using different teaching techniques. Teacher’s behaviour towards students was conducive for learning. Teachers treated discriminately, students did not complaint against teachers to the head of institutions. Teachers were friendly, approachable, cooperative competent, well prepared. There was significantly positive correlation between teacher’s behaviour and students academic achievement scores. Major recommendations of the study were, highly qualified teachers be appointed and their salaries be increased to enhance their performance. Students be encouraged to point out reasonable shortcomings of their teachers before the heads of institution. Teachers undue favouritism to some students be discouraged. Positive behaviour of the teachers be ensured at the time of their recruitment.