The author explains that international comparison of crime statistics is both desirable and complex. The author cautions that crime statistics from different countries cannot be directly compared. Criminologists and statisticians must take care to note the differences in crime definitions and the police practices for reporting and recording crimes. Among the most important considerations when comparing international crime statistics are the differences in legal systems and definitions of crimes, levels of justice system efficiency, and propensity of victims to report crimes, to name a few. The author then reviews international data sources concerning crime and victimization, including Interpol, the United Nations Survey on Crime Trends and the Operations of Criminal Justice System, the International Crime Victim Survey, and the European Sourcebook on Crime and Criminal Statistics. Comparing crime in different countries reveals that crime heavily affects developing nations and that reporting levels vary among countries, with less than 50 percent of crimes reported in developing countries. The author notes that an international strategy is necessary to integrate data and systematize concepts, definitions, and classifications.