This article focuses on the use of back region humor in two different professional settings in order to highlight the ways in which professional orientations are reflected in both topic selection and style of humor. The first part of the paper examines humor in a prototypical back region setting, the school staffroom, challenging the view that such staffrooms exhibit characteristics associated with a back region, where professional issues do not receive serious attention. In the second part, the school setting is compared with that of an agricultural research establishment and it is suggested that professional orientations may influence the nature of humor, even when topics have no direct relation to the work of those involved. The paper therefore provides support for the claim that humor is "a distinctive feature of workplace culture" (Holmes and Stubbe 2003: 134) and that different groups can be distinguished in terms of their preferences in this respect (Holmes and Marra 2002). However, it goes further in suggesting a link between styles of back region humor and professional orientation. The paper concludes with a discussion of the contribution that linguistic ethnography can make to the comparison of features of different social worlds.