This article examined the leadership effectiveness of department heads at a state university in Turkey using a model of leadership effectiveness that includes the use of multiple leadership roles to manage situations arising from internal and external university environments. Leadership effectiveness was measured by surveying 70 faculty members in three social sciences departments using a modified instrument based on the competing values managerial behaviour framework. The instrument also provided scores ranking the use by department heads of various leadership roles, which were categorized into four leadership functions. The top five leadership roles employed by department heads were: facilitator, producer, driver, innovator and mentor. Leadership functions were positively correlated with one another and with leadership effectiveness. Multiple regression analysis showed that the four leadership functions and the gender of survey respondents were significant predictors of leadership effectiveness. The strongest predictor of leadership effectiveness was the create leadership function, which includes motivator, visionary and innovator leadership roles.