Abstract Introduction The National Burn Repository (NBR) currently only contains inpatient data from participating United States burn centres. However, the majority of the patients treated in burn centres are managed as outpatients. Unfortunately, this significant demographic is not represented in the NBR annual report. The purpose of this study is to compare the difference in aetiology and demographics between inpatient and outpatient burn patients. In addition, the workload demands for data entry of inpatient and outpatient records in the burn registry will be compared. Methods Outpatient and inpatient burn data at an American Burn Association-Verified Burn Center were prospectively collected during fiscal year 2008. Data collected included age, burn size and aetiology of burn. Aetiology was also stratified by age group. Inpatient data were compared with outpatient data with Fisher's exact test. The amount of time taken to enter inpatients’ and outpatients’ data parameters in the TRACS v5.0 database was also recorded. Results Data were collected for 241 inpatients and for 543 outpatients during fiscal year 2008. No significant differences in gender or race were found between the two groups. When comparing demographics, outpatients tended to be younger (26 ± 19 years vs. 32 ± 22 years, p = 0.01) with a smaller burn size (2.5 ± 7% vs. 6.8 ± 12%, p < 0.001) and a lower frequency of full-thickness burns (17% vs. 41%, p < 0.001). Of the patients managed as an outpatient, a total 29.7% were eventually admitted to the hospital. Just over half of those (16.7%) initially managed in the outpatient setting were admitted for a planned surgical procedure. The other 13% were admitted for pain control and wound-care issues. Injury was more likely to be caused by flame in inpatients ( p < 0.001). Scald injuries were more common in the outpatient setting (34% vs. 27%), but this difference did not reach statistical significance ( p = 0.079). Outpatients were more likely to be injured with a contact burn ( p < 0.0001). Outpatient injury was more likely to be work-related than inpatient injury ( p = 0.0497), but less likely to be related to recreational activity ( p = 0.006) or arson/abuse/assault ( p = 0.0158). An experienced TRACSv5.0 user required 11 ± 0.6 min to enter an inpatient record and 6 ± 0.6 min to enter an outpatient record in the system ( p = 0.002). Conclusions Inpatient injury is more likely to be caused by flame, whereas outpatient injury is more likely to be caused by scald and contact burns. Work-related burn is more likely to be treated in the outpatient setting. Outpatient burn data also take less time to enter. Since significant differences in aetiology exist, outpatient data should be reported separately from inpatient data in order to understand the full spectrum of burn aetiology. The NBR and other registries should be modified to track outpatient burn data and outcomes.