Some researchers suggest that the way a teacher is perceived during the first encounter with a classroom group resembles, and therefore is predictive of, later classroom processes as perceived by students. This study investigated the degree to which interpersonal ratings (i.e., control and affiliation), given by secondary school students to teachers unknown to them, are comparable to ratings given by students who are well acquainted with that teacher, by means of a quasi-experimental design. Ratings concerning a teacher students had not met before, based on a 5 min video vignette, were compared to ratings given by students who had been taught by the same teacher for at least a year (N =489). Students at no acquaintance perceived a teacher's interpersonal traits in a similar way as students who were familiar with that teacher. It is concluded that students' early interpersonal perceptions of a teacher largely resemble perceptions formed by students that know this teacher well.