Gender diversity in corporate boardrooms and its relation to the financial performance of public companies is the subject of a wide debate. Both positive and negative relationships have been identified between these two phenomena. This study attempts to determine if there is a relationship between the representation of women on boards and the financial performance of companies in Poland. The research sample comprised 90 companies that had complete records of necessary data and were continuously listed on the Warsaw Stock Exchange in Poland from 2010 to 2019 (in a period referred to as the pre-COVID-19 pandemic decade). The financial performance of companies is measured by (1) several single financial ratios and (2) synthetic (taxonomic) measures constructed using sets of various individual financial ratios. Investigations were conducted for all the selected companies collectively, and separately for banks, other financial firms and non-financial companies. The findings indicate that women’s representation on boards had no connection to the financial performance of public companies in Poland, although a few examples of positive relation were noted, particularly in the case of banks.