Abstract Objectives: Odontogenic infections are frequent and can spread, leading to complications such as sepsis and the need for admission to an Intensive Care Unit (ICU). The purpose of this study was to perform a computed tomography analysis of the fascial space involvement and correlate with personal data, laboratory tests, length of hospital stays and admission to the ICU in patients with odontogenic infections who required hospitalization. Methods: Patients with odontogenic infections admitted between June 2017 and May 2018 were prospectively evaluated. The fascial spaces involved were studied using computed tomography with contrast. The possible correlations of tomographic findings with comorbidities, nutritional status, the causative tooth, laboratory tests, length of hospital stays and admission to the ICU were analyzed. Results: We identified 66 cases of odontogenic infections which were admitted in the period analyzed. The involvement of primary spaces (86.7%) predominated, followed by secondary ones (8.7%), and cervical (4.6%). The most frequently involved fascial spaces were submandibular (27.1%), buccal (20.8%), sublingual (18.3%), submental (16.7%), and others (17.1%). There were significant differences between laboratory tests (p < 0.001), mean hospital stays (p < 0.001), and admissions to the ICU (p < 0.001) depending on the number of fascial spaces involved. There was no influence of comorbidities, nutritional status, or causative tooth on fascial space involvement. Conclusion: There was a relationship between greater involvement of fascial spaces assessed by computed tomography and higher values of laboratory tests, more extended hospitalization stays and admission to the ICU. Level of evidence: Level 2b.