Purpose: This paper aims to investigate the determinants of women representation on Australian corporate boards under the ASX’s "if not, why not" corporate governance framework. It further aims to improve the study of Geiger and Marlin (2012) by using a theoretically sound two-limit Tobit model to examine the determinants.

Design/methodology/approach: This study uses the two-limit Tobit model to examine the determinants of women representation on ASX 500 boards. This approach is used due to the censored nature of the dependent variable.

Findings: This study finds that the two-limit Tobit model is an appropriate methodology to accommodate the censored dependent variable. It further finds that firm size, women as chair of boards, corporate governance index, Global Reporting Initiative signatory, debt ratio, average board age, BIG4 auditors, chief executive officer tenure and shareholder concentration are major determinants of women on boards.

Research limitations/implications: The use of only ASX 500 companies and the sample years (2011-2014) may limit the generalisation of the findings.

Originality/value: This is the first extensive longitudinal Australian study to examine the drivers of women representation on corporate boards. It is also the first of its kind to use the two-limit Tobit model to consider these determinants.