The present research provides the first analyses of Australian women directors from the perspective of social identity theory. The overall objective of the research program is to confirm the validity of social identity theory to the study of women on corporate boards and in doing so, add to the limited knowledge regarding successful women directors. An aim of the research was to identify factors that are significant in the social identity of women who are successful directors of corporate boards. These factors were revealed through a longitudinal study (over six years) of changes in the demographic characteristics of the women and their board positions. Factors were revealed through their perceptions of their effectiveness as an ostensibly minority (female) board member. Similarities in stereotyped attitudes to men and women board directors confirmed their status as an ingroup member. Through identification of significant factors in women’s success as board directors it is hoped to assist both individual women who are striving for success on corporate boards and organisations who wish to make more effective use of women on their boards. Five studies examined various aspects of women directors’ experiences and influences through three survey instruments that were used to collect data over a period of six years. A survey design allowed the gathering of detailed data on a variety of items thought to be relevant to women’s experiences of being directors and allowed the data collected to be oriented to a theoretical framework. Thus, a survey design was deemed superior to common alternatives of analysis of archival company annual report data or re-analysis of data collected by executive search companies for a study of corporate directors. A survey of 572 Australian women directors in 1995 identified many characteristics of women directors. A profile of a typical Australian women director was constructed and compared to international research on women directors covering a similar period (e.g., Burke, 1994b; Catalyst, 1993; Holton, Rabbets & Scrivener, 1993). An examination of differences between the characteristics of executive and nonexecutive women directors confirmed that the two director roles could be perceived as distinct groups. A further survey of the women six years later examined changes in their characteristics and board experiences. Of the 298 women who had agreed to follow-up research, 59 surveys were returned as no longer at the same address, 23 women indicated that they were no longer on a corporate board, and 32 were current corporate directors. Changes in the women’s profiles that the directors had attained through increased board memberships and more central board roles were interpreted as indicators of success. Based on research by Cejka and Eagly (1999), similarities and differences in stereotypical attitudes of men and women directors were examined in relation to social identity theory. Factors in nonexecutive women directors’ identification as board directors, their perceptions of their ability to contribute as board directors, and their behaviour as a board directors were assessed by measures from Karasawa (1991) and Westphal and Milton (2000). The present research program demonstrated the value of social identity theory as a vehicle for understanding Australian women director’s experiences on corporate boards. For the present research, social identity theory provided insights into how successful Australian women directors perceive themselves and other members of their ingroup of board directors. By contributing to a deeper understanding of successful women directors, it is hoped that a greater number of women will be able to successfully join ingroups of board directors, thereby breaking down the barriers to women.