Fournier's gangrene (FG) is a devastating and potentially fatal disease requiring prompt and aggressive debridement. In this study, it was aimed to assess the predictors of mortality in a large cohort. Prospectively maintained data of patients with FG were analyzed. Demographic data, duration of symptoms, Uludag Fournier's Gangrene Severity Index (UFGSI) scores, co-morbidities [particularly diabetes mellitus (DM)], etiologies, number of debridement, stoma requirements, length of intensive care unit and hospital stay, and morbidity and mortality rates were reviewed. Multivariate analysis was performed in order to determine factors affecting mortality. 120 patients (81 males) were included in the study. Median age was 58 (22-85) years. UFGSI score was median 9 (1-30). DM was present in 69 (57.5%) patients. Etiology of FG was perianal in fifty-nine, urogenital in 52, and skin in 9 patients. Median debridement count was 3 (1-12). Thirty-one patients required stoma. Forty-eight patients were admitted to intensive care unit and 25 patients required mechanical ventilation. Overall mortality rate was 20.8%. Multivariate analysis revealed UFGSI as the only predictor of mortality (p=0.001). Mortality rate was 13.64 times higher for patients with a UFGSI score of 9 or higher. Fournier's gangrene is a mortal disease requiring emergency surgery. UFGSI is an efficient predictor of mortality for patients with FG.