The first attempts at quantified international comparisons date back as early as the 19th century. Attempts to harmonize national criminal statistics were high on the agenda of the first international conference on statistics in Brussels in 1853. However, there were two schools of thought that clashed in 1853 that continue to persist causing the harmonization of statistics on crime to still remain a distant goal. This article attempts to address the issues continuing to plague the ability for international criminal justice statistics comparisons to be conducted. It begins by first discussing several initiatives, in the form of international surveys that have been developed to assist in better harmonization and comparable findings. It continues with a review of the European Sourcebook. One of the difficulties in using international collections of statistics has resided in the lack of systematic information on factors of non-comparability. In 1993, a group of European experts began the design of a more detailed method of data collection based on more direct relations between the individual participants of the Sourcebook. The Sourcebook chose to seek better comparability between countries by limiting itself to a selection of accurately defined offenses; homicide, assault, rape, robbery, other thefts, theft of motor vehicles, and drug offenses. The questionnaire utilized for the Sourcebook on statistical methods goes into detail on the definition of counting units and recording points. In addition, there is close scrutiny of the results provided by national correspondents. Findings from the second edition Sourcebook, covering 1995 to 2000 and utilizing revised data collection methods and factors, are presented.