In 2001, Emergency Department (ED) staff at the six hospitals providing emergency medical care within the city collected data on all assault-related ED visits. Individual-level (n = 1,204) and neighborhood-level (n = 262) analyses were conducted; the latter used data from the 2000 U.S. Census. A hotspots map was also generated. At the individual level, one in three ED patients was assaulted by an intimate partner or other family member. In addition, African-American males were disproportionately likely to be treated for assault-related injuries. At the socio-structural level, as hypothesized based on Social Disorganization Theory, hierarchical regression analyses reveal that poorer neighborhoods with more vacant housing units have significantly higher rates of assault-related injuries. (Published Abstract)