The operating room (OR) is one of the most expensive facilities in most hospitals. The demands on a professional and process-oriented controlling and reporting in the OR are increased due to the increasingly more limited financial margins at the end of the diagnosis related groups (DRG) convergence phase. This study gives an overview of the current situation for cost calculation, controlling and reporting in OR management in German hospitals in 2007. The data from 69 hospitals were evaluated and this represents the largest currently available data pool on this topic.