Terrorism has been one of the major concerns of societies, governments, policy makers, and academicians especially after 9/11. An increase or decrease in trends of terrorism fatalities were regarded as predictors of success or failure of public policies in combating terrorism. In the terrorism literature, it's controversial whether the terrorism related incidents increased continuously as well as fatalities [1]. Despite the notion that fatalities due to terrorism have an upward trend in the world in general in the last few decades, there are still questions with regard the trends in lethality of terrorism. This study presented findings of statistical tests using official datasets covered all terror incidents occurred in Istanbul, Turkey between 1999 and 2009 in an attempt to find empirical evidence regarding the lethality of terrorism as well as some of its correlates. Tests sought correlations among types of terror incidents, identity of terrorist organizations, their targets, modus operandi and fatality rate of terror attacks. The study provided essential information about terrorist attacks' fatality rate and factors affecting them for the practitioners in charge of preventing future terrorist attacks on an example of diversely populated city.