The mortality rate following burn is an important outcome parameter. This study aimed to identify factors associated with mortality in adult hospitalized burn patients in Tehran, Iran.This cross-sectional study was performed during a one-year period in two referral burn centers in Tehran. During the study period, 1321 adult (> 15 years) hospitalized burn patients were enrolled. Univariate and multivariate (logistic regression) analyses were performed to identify factors associated with mortality.The mean age of the patients was 33.1 ± 14.9 years. By far, the majority of burns were accidental (n = 1076, 81.5%). Regarding the mechanism of burn, burn with petroleum products was the most frequent. Mean percent burned total body surface area (TBSA) was 39.9% ± 25.8%. The mortality rate was 33%. Sepsis was the most common cause of mortality. The results of the present study indicated that non work-related burns, burned TBSA and body surface area affected by second- or third-degree burns were independent determinants of mortality among adult hospitalized burn patients.The present study showed a high mortality rate in the studied burn centers. Patients with identified risk factors should be categorized as high risk at the time of admission and need special attention and care during hospitalization.