To simplify the task, the focus is on 34 quantitative studies that have attempted to explain variations in the homicide rates of different countries. These studies are in English and include cross-national homicide rates as a dependent variable. Sources of data for cross-national studies of homicide are reviewed; these are the International Criminal Police Organization (Interpol), the World Health Organization, the United Nations, the Comparative Crime Data File, and the Human Relations Area Files. Methodological issues in cross-national comparative studies of homicide are then identified and discussed, followed by sections that address comparison of data sources, a listing of cross-national homicide rates, theoretical perspectives on cross-national homicide, and generalizations of findings from cross-national comparative studies. Theoretical perspectives on cross-national homicide encompass modernization/social disorganization, economic stress, and situational perspectives. The generalizations of findings from cross-national comparative studies address homicides versus property crimes, economic development and industrialization, economic inequality, unemployment and homicide, urbanism and homicide, disaggregated homicide rates, population structure, and social and cultural heterogeneity. Implications are drawn for theories of cross-national homicide. 2 tables, 3 notes, and 70 references