The system of Payment by Results (PbR) was instituted in 2005 to reimburse secondary care for its activity. One of the features of PbR is the short stay tariff (SST), in which only 20-50% of the national tariff is paid if patients have a length of stay (LoS) of less than 2 days in hospital for certain Healthcare Resource Groups (HRGs) - or conditions. We analysed the admissions under Acute Medicine at Bradford Teaching Hospitals over a period of one year and identified the HRGs to which the SST applied. We used the 2007 PbR national tariff to calculate the additional income that would have been generated if these patients were kept in hospital for at least 2 days in order to avoid SST. We calculated an extra theoretical income of approximately £5 million if all these patients had a length of stay (LoS) more than 2 days to avoid the SST. Sixteen additional beds (assuming 85% occupancy) would have been required at a cost of around £1million per year to accommodate these patients. We show that the current PbR system is flawed and penalises hospitals with a higher turnover of patients.