This paper compares the practice of holding prime ministers to account in four case studies: Australia, Canada, Ireland, and the United Kingdom. Using text analysis, as well as research on prime ministerial responsibilities, it investigates oral questions asked in parliamentary procedures where prime ministers are questioned together with ministers (Question Period in Canada and Question Time in Australia) versus procedures where they are questioned individually (PMQs in the United Kingdom and Oral Questions to the Taoiseach in Ireland), and explores the degree to which they are questioned for matters that are within their remit. It argues that the practice of prime ministerial accountability is decisively shaped by procedural features such as whether written notice is required for questions, as well as by the broader role of the questioning mechanism in the political system, and less by the collective or individualised nature of questioning. [ABSTRACT FROM AUTHOR]