This study examined relationships among demographic diversity (education, gender, tenure and managerial level), organisational commitment, efficacy, citizenship behaviours and performance outcomes within Australian local councils. Data from local council employees indicated significant relationships between demographic diversity and all criterion variables. In theoretical terms, the study extended our understanding of how demographic diversity was associated with employees’ organisational commitment, collective efficacy beliefs and outcomes expectancy, organisational efficacy, organisational citizenship behaviours, performance outcomes and leadership. The level of education, number of men in a work unit, length of time the work unit worked together and managerial level were associated with performance outcomes, organisational citizenship behaviours, efficacy and organisational commitment. Further theoretical and managerial implications following on from this study are discussed.