The introduction of the DRG system in Germany-optional since 1 January 2003 and mandatory for all hospitals as of 1 January 2004-has resulted in great uncertainty, particularly on the part of hospitals, since apprehension prevails that the diagnostic and therapeutic measures practiced in Germany will not be appropriately represented and remunerated by a DRG system. The G-DRG version 1.0 prepared within the framework of substitutive execution is largely identical to the Australian AR-DRG version 4.1. Adjustments that do justice to the realities of German treatment modalities were at most insignificant. It is therefore essential that stock be taken for each medical specialty to determine to what extent treatment procedures commonly followed in Germany are adequately reflected in this G-DRG system or whether adjustments are necessary to make allowances for German realities. To be able to provide qualified statements on the problems involved, scientific analysis of possible problems is necessary utilizing German data. Thus, we undertook an evaluation of how the special fields of orthopedics and accident surgery are represented in the G-DRG system. The resultant data form the basis for evidence of presumable deficits in the representation of orthopedic and accident surgery cases in the G-DRG system. The German Association for Trauma Surgery and the German Association for Orthopedics and Orthopedic Surgery have undertaken a DRG evaluation project together with the Organization of Directors for Accident Surgery (chairperson: Professor Dr. Mischkowsky, Kempten), the Organization of Directors for Orthopedics (chairperson: Professor Dr. Puhl, Ulm), the DRG Working Group of the German Association for Accident Surgery, and the Joint Commission of the Professional Association of German Surgeons and the German Association for Surgery in cooperation with the DRG Research Group of the University Clinic Muenster, the German Hospital Association, and the German Medical Association with the goal of examining the medical and economic homogeneity of the case groups. A total of 12,645 orthopedic and trauma surgery cases were collected from 23 clinics-11 university hospitals and 12 non-university hospitals-and assessed. On the basis of this database and when too few cases were evaluable also based on clinical considerations, 14 adjustment proposals were formulated and submitted on schedule on 31 March 2003 to the Institute for Hospital Remuneration. The results of the DRG evaluation project illustrated the problems involved in representing the exceedingly heterogeneous and complex activities of orthopedic and trauma surgery departments in a flat rate financing system that is not attuned to the realties of German treatment procedures. Version 1.0 of the G-DRG system is not sufficiently differentiated to represent the multifaceted diagnostic and therapeutic services provided by trauma surgery and orthopedic departments in Germany.