To evaluate treatment outcomes in patients with severe maxillofacial infections requiring hospital care during a 17-year period. A retrospective cohort study reviewed 5,465 medical records, and the following data were collected: the reason for infection, locations of inflamed regions, treatment provided, bacteriological findings, and treatment outcomes. Other information included sociodemographic characteristics (age, gender), presence of systemic diseases, and smoking history. The annual incidence rate of patients with acute maxillofacial infections was 206±19 cases with a male to female ratio 1.4:1.0, a mean hospital stay of 7.9±4.9days. Older age (>65years), smoking and systemic diseases (diabetes), the causative tooth (molar), and need for extraoral incision predicted longer hospitalization. Intravenous penicillin was the most common drug prescribed in 50.5% of cases. A total of 132 different microorganisms were identified. The highest microorganism resistance occurred for metronidazole and the highest sensitivity was to clindamycin. Increased age, smoking, diabetes, causative tooth, and the occurrence of several infected spaces were associated with a longer hospital stay. Streptococcus α haemolyticus was the most common microorganism found in more than 70.0% of cases that were sensitive to intravenous penicillin.