The under-representation of women in Science, Technology, Engineering and Mathematics (STEM) disciplines has been well documented. We discuss an affirmative action recruitment strategy from the University of Melbourne's STEM disciplines where only female applicants were eligible to apply for academic positions. This strategy has been very successful in attracting high-calibre female applicants, with more than the original target of women being recruited. This affirmative action recruitment strategy was not intended to be undertaken on an ongoing basis. We show that by undertaking one round of affirmative action recruitment, it signalled to prospective female applicants that the university is committed to gender equity. This resulted in more female STEM applicants applying in subsequent open recruitment rounds. We discuss the rationale behind this strategy, its allowance under the Equal Opportunity Act 2010, Victoria, Australia, and the results achieved. We also address challenges faced and lessons learned.