Since the criteria for diagnosis of childhood attention-deficit/hyperactivity disorder (AD/HD) include that the symptoms present in at least two situations, usually home and school, the role of teachers in the identification and diagnosis of this condition is crucial. There is, however, evidence of inter-cultural differences in ratings of AD/HD in children and young people, by teachers and others, though it is not possible to make comparisons between the various studies, because the conditions were not comparable. The focus of this article is the cultural influences on ratings of AD/HD-type behaviour. Evidence is presented of culturally related differences in such ratings, under conditions designed to ensure directly comparable conditions, involving teachers and student teachers from mainland China, Hong Kong, and the United Kingdom. There was some evidence that the teachers from mainland China rated the behaviour of a "target" child, presented on video, higher on a number of items than either the teachers from Hong Kong or the United Kingdom. There was only limited evidence of differences between the ratings of teachers and student teachers within the same culture.[Copyright of International Journal of Disability, Development and Education is the property of Routledge. Full article may be available at the publisher's website: http://dx.doi.org/10.1080/1034912022000007298]