Purpose – This paper seeks to investigate the corporate governance determinants of financial instrument disclosure (FID) practices of Australian listed resource firms in their annual reports for the 2005 financial year. This is an important time period to explain FID patterns for Australian resource companies leading up to formal adoption of the Australian equivalents to the International Financial Reporting Standards (IFRS). Design/methodology/approach – The extent of FID was measured using a Financial Instrument Disclosure Index (FIDI) comprised of 120 items of both mandatory and discretionary financial instrument information. Hypothesis testing used empirical data from a representative sample of Australian listed resource firms. Research limitations/implications – The results of regression analysis demonstrate that corporate governance characteristics of firms are significant determinants of FID patterns. Univariate and multivariate results showed that FIDs were significantly and positively associated with strength of corporate governance structure and the control variables – leverage, firm size and industry. Originality/value – This paper contributes to an emerging paradigm that emphasises the link between firms' governance structures and their disclosure responses to financial instruments and in particular, financial derivatives.