Firearm injuries are a leading cause of violent death in Tennessee. This study was designed to compare the demographic and epidemiologic features of fatal firearm injuries in Shelby County and Davidson County, Tennessee between 2009 and 2012. We identified 1081 gunshot fatalities for the study period in these two counties. Shelby County had a higher overall, age-adjusted gunshot mortality rate, a higher male age-adjusted gunshot mortality rate, and a higher age-adjusted gunshot homicide rate than Davidson. Age groups 25–34 years and 35–44 years had higher crude mortality rates for gunshot deaths in Shelby County than Davidson County. Both counties had higher age-adjusted gunshot mortality rates for black males than white males, higher homicide rate for black race than white, and higher suicide rate for white race than black. Homicide was the most common manner of death, and handguns were the most common type of firearm used in both counties.