Background: This article reports a study into the double marking of Liberal Studies in Hong Kong. This is now a compulsory subject in Hong Kong's Years 10-12 curriculum which, when first examined in the new Hong Kong Diploma of Secondary Education in 2012, will increase its candidature from its current 3,300 to 80,000. Aims: To examine the reliability of the forthcoming double marking of LS, investigating whether high inter-marker correlations are achieved in the double marking of LS, matching the reliability rate achieved by other examinations administered by the HKEAA. Method: Broadly adopting the methodology of an earlier study of marking in the 2007 Year 11 English Language examination, the current study investigates double marking using classical test statistics--inter-, intra- and marker-subject correlations--and the amount of discrepancy between pairs of markers. Sample: Seven experienced markers (re)marked 677 scripts from the "Hong Kong Studies" module and another seven markers (re)marked 654 scripts from the Human Relationships module. Results: Moderate to strong correlations emerged between pairs of markers. Discrepancy levels were below 10%--in line with other Hong Kong public examinations. Conclusion: With a view to improving marker reliability, the study concludes with the recommendation that the current holistic marking scheme should be re-evaluated, with a view to investigating its replacement by an analytic, domain-based marking scheme. This study highlights the need for public examination bodies to carry out a range of validation, reliability and other studies prior to the implementation of changes to their large-scale examinations. (Contains 4 tables.)