This study was interested in determining whether ethnicity-based cultural differences affected knowledge usage in today's multicultural organizations. Our empirical study uses a psychology-based approach to measure what we refer to as implicit managerial knowledge of Information and Communication Technology (ICT) workers within three Australian organizations. The research instrument captures responses to various ICT workplace scenarios in order to determine and compare the different ways in which people make use of the implicit knowledge they use to manage themselves and others. Using the culture-based literature to assist with interpretation of the data, we have identified a number of themes and their characteristics and brought these together to provide a comprehensive model for understanding cultural influences. This model can be used to better appreciate why and perhaps anticipate how an individual's implicit managerial knowledge will be used in responding to everyday workplace situations. Such an understanding will assist organizations to develop appropriate and effective knowledge management strategies.