The Queensland Coal Mining Safety and Health Act 1999 and the Mining and Quarrying Safety and Health Act 1999 require a mine to have a Safety and Health Management System (SHMS) in place to manage the risk to safety and health of persons at the mine. The legislation assigns the obligation to the site senior executive to develop and implement the mine’s SHMS. It assigns a further obligation to the mine operator to audit the effectiveness of the system put in place by the site senior executive. What is exactly meant in the legislation by the term effectiveness, and how to go about assessing effectiveness has been the topic of much debate since the legislation was enacted. In 2008, the Queensland Mines Inspectorate provided some clarification on the issue, when it published Queensland Guidance Note QGN09 Reviewing the Effectiveness of Safety and Health Management Systems. However, QGN09 is not an exhaustive treatment of reviewing the effectiveness of an SHMS. In this paper, former Queensland Commissioner for Mine Safety and Health, Paul Harrison, and former Queensland Chief Inspector of Mines, Phil Goode, discuss effectiveness audits from the perspective of the authors’ experience and propose a tool for quantitative measurement of SHMS effectiveness.