This article explores the process of constituting 'professionalism' as a discursive category amongst migrant academics working in Thailand. We animate the conceptual resource of 'category boundary work' to examine the inclusionary and exclusionary practices by which 'un/professionalism' is produced in the talk of 25 "aa-jaan dtàang châat" or migrant academics working in Thailand. Throughout our data, the discourse of professionalism was constructed in opposition to three key storylines which constituted the 'unprofessional migrant academic' as morally questionable; underqualified; and uncommitted. We argue that the constitution of unprofessionalism matters, producing tangible effects for higher education institutions and academic workers alike.