We investigated the precision of Supplementary Homicide Report (SHR) homicide rate estimates for large U.S. cities during the 5 years, 1998-2002. The homicide rates based on the National Vital Statistics System provided a parallel measure and the basis for estimating the reliability and average error. When cities with incomplete SHR data were removed from the sample, the estimated reliability was high (.99), and the standard error of measurement was low (1.2 homicides per 100,000 residents). Reliability remained high for subsets of cities and for most subsets of victims. For some groups, however, such as African Americans and persons age 0 to 14, the reliability was much lower.