The high-stakes public examinations which mark the end of upper secondary education have been and still are a common feature of most education systems. These high-stake curriculum-based assessments, irrespective of the form of such assessments, are based on a specifically drawn- up programme or syllabi approved by the relevant educational bodies. Literature has shown that as well as providing a framework within which to assess the alignment of the examinations with the associated curricula, Bloom’s revised taxonomy can facilitate the comparison of the cognitive skills of high-stakes examinations of different education systems. Between 1966 and 2016, three different syllabi in physics and chemistry were implemented at the upper secondary level in Irish Schools. This thesis focused on the cognitive demands of the Leaving Certificate examinations in physics and chemistry during this period. Using Bloom’s taxonomy as the framework, a two-study approach was adopted. The first study focused on the cognitive demands of the questions as presented in the physics and chemistry Leaving Certificate examinations. Using a defined list of action-verbs associated with Bloom’s revised taxonomy as the analytic tool, the second study compared the cognitive demands of the 2016 high-stakes written examinations in six countries ( England, Ireland, the Netherlands, New South Wales, South Africa and Scotland). The examination year 2016 was selected as the syllabi and examination system of these six countries had not changed in the two previous years, with similar topics being examined. This study included a comparison of cognitive demands across comparable topics in these examinations. Findings from these two studies are discussed within the context of developing and promoting the use of questions which assess higher cognitive demands of analyse, evaluate and create in these high-stakes examinations at the end of upper second-level education.