High-cost users generate extremely high costs when compared with average users in the same diagnostic-related group (DRG). They represent a major financial loss for a health service organization. The research was conducted using an area health service patient database for online analytical processing to produce descriptive statistics and graphs of 'high-cost' and 'non-high-cost users'. Trends and patterns were identified across key variables derived from clinical, financial and operational categories. The main results are: 20% of costs are spent by 3% of the population; elective admission is higher in the high-cost group; tracheostomy has the most number of cases and is the most expensive DRG; LOS is mostly longer for complex cases however, high costs can be attributed to other factors. In conclusion, these findings are potentially useful to patients, medical staff, management and health service decision-makers. The limitation of this study is the exclusion of profitability.