Patients and health insurances are increasingly interested in the quality of care provided by hospitals. Quality indicators are often used to evaluate the quality of inpatient treatment. Most of these evaluations require the collection of additional data. The patient safety indicators (PSI) introduced by the Agency for Healthcare Research and Quality (AHRQ) are precisely validated and exclusively depend on routine data. The original PSI definitions were transferable to the classifications of diagnosis, procedures and DRG used in Germany, and applied to routine data of 2.3 million cases from more than 200 hospitals. The comparison of the results to the US references reveals high concordance between the rates and demonstrates that PSI can be applied to detect critical incidents of patient care. For PSI-based hospital benchmarking further development of appropriate methods of risk adjustment is necessary.