The review paper consists of five parts. First, a brief characteristic of the main trends in teacher research and classroom interaction and communication research are explained. Then a detailed presentation is provided of the personality theory based on the Leary model of interpersonal behaviour, including its educational implications, as proposed by researches from the University of Utrecht. The third part of the paper describes assessment methods which are based on the theory of teacher interpersonal behaviour, i.e. standardised observation of a teacher and the Questionnaire on Teacher interaction, as used by pupils, headmasters, supervising teachers, etc. The fourth part of the paper summarizes the findings of the research of teacher interpersonal behaviour. Findings are presented of determinants such as gender, ethnicity, years of teaching practice of a teacher, teaching subjects, grades, class composition, classroom social climate, etc. The fifth part discusses the limits of the methods of assessment of the interpersonal behaviour of teachers.