The globalisation of education has meant that English medium universities are enrolling unprecedented numbers of students for whom English is not a first language. This, in turn, has put increased pressure on institutions to ensure they have in place suitable measures for screening applicants in respect of their English language proficiency and providing suitable support post-entry for those students who succeed in meeting English language entry criteria but still struggle to meet the linguistic demands of their programmes of study. In Australia, efforts to improve these processes have recently been galvanised by new regulatory requirements, one effect of which has been a significant increase in activity around the area of post-enrolment language assessment, with the purpose of identifying all students potentially at risk and ensuring, subsequently, that mechanisms are in place that promise to address their language needs effectively. This article considers some of the issues around post-enrolment English language assessment, discusses possible permutations for its implementation, and argues that, in determining the focus of such assessment, it is helpful to deconstruct the generic term "proficiency." (Contains 2 footnotes.)