Several previous studies have investigated the use of questions to facilitate interactions in academic lectures in tertiary education. However, the issue of how disciplinary cultures influence the patterns of questions in lectures has received little attention. Therefore, this study aims to examine the interdisciplinary differences in professors' use of questions in terms of both their forms and functions. The corpus used in this study consists of 15 small-class lectures from three academic divisions: Humanities & Arts (HA), Social Sciences & Education (SS) and Physical Sciences & Engineering (PS). These data are a subset of the Michigan Corpus of Academic Spoken English (MICASE). Previous studies on academic spoken English have reported that, compared with other contextual factors, the disciplinary culture seems to exert a more critical influence on the use of various linguistic features. However, the results of this study show far more similarities than differences across different disciplines. Based on the major findings pertaining to the use of question forms and functions across the three divisions, it is suggested that for questions in academic lectures at the tertiary level, the influence of genre seems to outweigh that of disciplinary culture. (Contains 1 figure and 8 tables.)