Purpose – This paper firstly measure the impact of Board of Directors (BOD); audit committee (AC) and Sharia Supervisory Board (SSB) composition (gender diversity) on earningsquality (EQ) in the Islamic banks (IBs). Secondly, we measure to what extent adoption of IFRS and national culture, which is proxies by Femininity can, moderates the relationship between diversity and EQ. Design/methodology/approach – Hypotheses are tested using pooled OLS-regression models. Our sample comprises 122 IBs across 21 different countries from 2010 to 2017. Our sample include 46 IBs adopter of IFRS and 76 IBs that non-adopter of IFRS as local or Islamic standards. Findings – Evidence reveals that gender diversity in BOD, AC, and SSB is positively associated with EQ activities. Further, adoption IFRS standards by IBs significantly moderate the positive link between board diversity and EQ while shows significantly moderate the negative association between board diversity and EQ for banks that are non-adopter of IFRS. Concerned with the impact of culture; we find that culture dimension of femininity serve as informal institutional forces that influence the association between diversity and EQ. Some results hold and others altered after a number of robustness checks. Originality/value – This study is unique in providing IBs evidence for the moderating effect of accounting standards' adoption and culture on the link between the demographic features of BOD, AC and SSB members and firm outcome. The present study provides a new and far-reaching contribution into the debate about EQ in the context of ethical institutions as IBs as well as contribution into the debate about role of women in board in the context on countries characterized by masculinity community as MENA region or across Muslim countries. Practical implications – The findings have important implications for policymakers, regulators, and investors in their attempts to enhance EQ practices and improve financial reporting quality for IBs.