The global nature of today's business environment, coupled with technological advances, compels managers to work with an increasingly diverse workforce worldwide. The purpose of this multiple-case study was to explore how bank managers used employee diversity effectively in the organizational decision-making process. Participants were 10 frontline management staff (middle and executive managers) with the required employee engagement skills involved in the decision-making process of a Nigerian bank. The conceptual framework for this study was rational choice theory, also called rational action theory or choice theory. Participants responded to 8 open-ended semistructured interview questions. The data collection process included validating and triangulating information gathered via member checking and review of archival business documents and peer-reviewed journals. Thematic analysis was used to analyze data from the study. Five key themes emerged from data analysis: recruitment, retention, and improvement of diverse talents; education and integration of employees with a divergent institutional heritage; engagement and leveraging of diverse stakeholders; business innovation, and productivity; and decision-making, and profitability. The implications of this study for social change include employee diversity management and strategic practices that contribute to effective decision-making process in the organization to improve socio-economic development of stakeholders (customers, board of directors, employees, policymakers and business contractors) and promote cohesion within bank staff and stakeholders resulting to improved business relationship and tolerance in society.