This paper analyses laughter in spoken academic discourse, with the aim of discovering why lecturers provoke laughter in their lectures. A further purpose of the paper is to identify episodes in British data which may differ from those in other cultural contexts where other lecturing practices prevail, and thus to inform the design of study skills and staff development programmes for multilingual, multicultural, international university environments. Examination of the data indicates that the management of laughter in British lectures is strategic, and has a rhetorical purpose. Six main types of laughter episode are described: "teasing", "lecturer error", "self-deprecation", "black humour", "disparagement" and "word play". Laughter results from references to shared "scripts" for student and lecturer behaviour, evaluations of outsiders who do not form part of the lecturer-student in-group, and the lecturers' efforts to forge group intimacy. It serves as a means of maintaining social order, building rapport, relieving tension, and modelling academic and professional identities. Comparisons of laughter episodes across cultures, however, suggest that references to conventional British lecturer and student scripts would be out of place in many non-British contexts. (Contains 5 tables.)