In a study designed to examine differential teacher expectations towards disruptive and nondisruptive students, Hong Kong Secondary School teachers were asked to imagine two male pupils new to their class, who were (comparatively) badly-behaved and well-behaved respectively. Teachers were asked to indicate the probability that each pupil would display each of a range of twenty characteristics. Teachers appeared to have very different expectations regarding the personal characteristics shown by the two pupils. These expectations encompassed intellect and maturity, interpersonal and work-oriented attitudes and behaviour, interests, home background and even physical appearance. In every case the most unfavourable expectations were towards the disruptive student. Teachers held broadly similar expectations towards disruptive students, regardless of the ability level of the school in which they taught. The same was true for nondisruptive students. Consequently, many of the differential expectations displayed towards disruptive and nondisruptive students observed in the entire sample of teachers also extended to teachers in both the highest-ability and lowest-ability schools. Expectations seemed unrelated to the subject matter taught. However, the sex of the teacher appeared to have an effect on the expectations displayed, with female teachers displaying more positive expectations towards the disruptive student.