Two of every three American homicide victims are killed with firearms, yet little is known about the role played by household firearms in homicide victimization. The present study is the first to examine the cross sectional association between household firearm ownership and homicide victimization across the 50 US states, by age and gender, using nationally representative state-level survey-based estimates of household firearm ownership. Household firearm prevalence for each of the 50 states was obtained from the 2001 Behavioral Risk Factor Surveillance System. Homicide mortality data for each state were aggregated over the three-year study period, 2001-2003. Analyses controlled for state-level rates of aggravated assault, robbery, unemployment, urbanization, per capita alcohol consumption, and a resource deprivation index (a construct that includes median family income, the percentage of families living beneath the poverty line, the Gini index of family income inequality, the percentage of the population that is black and the percentage of families headed by a single female parent). Multivariate analyses found that states with higher rates of household firearm ownership had significantly higher homicide victimization rates of men, women and children. The association between firearm prevalence and homicide victimization in our study was driven by gun-related homicide victimization rates; non-gun-related victimization rates were not significantly associated with rates of firearm ownership. Although causal inference is not warranted on the basis of the present study alone, our findings suggest that the household may be an important source of firearms used to kill men, women and children in the United States.