OBJECTIVES: To review the experience with an on-site medical tent for a mass gathering and to analyze patient records in a manner to more appropriately allocate resources and identify possible delays in definitive care. METHODS: The logistics of providing an on-site medical tent is reviewed, followed by a retrospective chart review of 126 patients over a two-year period. Prior to the chart review, an injury classification was developed that categorized patients based on the necessity of transport to hospital. Data were also analyzed for times of peak patient flow, types of injuries, and needless delays in definitive care. RESULTS: An average of 63 patients (95% CI 44-77) were seen in the tent and 1.3 patients sought care per 10,000 spectators. Peak times were between 1600 and 2000 hours. The average number of patients each hour was 6.5 (95% CI 0-13). Severe, intermediate, and minor injuries accounted for 16%, 38%, and 46% of total injuries, respectively. Nine cases were found where the patients arrived and left the medical tent by ambulance. Four of these instances may have represented a needless delay in definitive care. The details of each of these cases are reviewed. CONCLUSIONS: The results indicate that on-site medical coverage, with appropriate supports, is indeed safe. The frame-work provided with regard to setup and analysis of work-load will help others in the planning of medical care for similar mass gatherings.