Background/Aim: There are few studies in the literature evaluating possible alterations in laboratory tests in patients with maxillofacial fractures. The aim of this study was to analyze the changes in admission laboratory tests of patients with maxillofacial fractures with indications for surgical treatment, including the influence of dento-alveolar trauma.Material and Methods: Data from complete blood counts, blood coagulation tests, blood chemistries, and urinalysis results were obtained. The occurrence of concomitant dento-alveolar trauma was noted. The medical records were also re-evaluated later to verify the treatment outcome and the occurrence of complications. Statistical analyses were performed using the likelihood-ratio test to verify significant changes in the evaluated parameters (P ≤ .050). Results:There was a prevalence of males (78%) with a mean age of 35.9 years. Lower erythrocyte counts, hemoglobin levels, and/or hematocrit were observed in males with associated fractures and with simultaneous dento-alveolar fractures. Higher mean neutrophil, segmented neutrophil, and lymphocyte counts were observed in patients with simultaneous dento-alveolar trauma. A higher mean activated partial thromboplastin time (aPTT) ratio was also observed. Lower potassium levels were observed for patients in the fourth decade of life. Higher leukocyte counts not associated with trauma were observed in the urinalysis results of females and in the group of patients aged 20 or younger. Verification of treatment outcome showed two cases of infections and two cases that needed re-operation after mandible fractures.These four cases showed no significant changes in laboratory tests regarding the predisposition for complications. Conclusion:Patients with maxillofacial fractures had neutrophilia, increased aPTT, and non-traumatic leukocyturia. There was an influence of associated fractures and dento-alveolar trauma on the decrease in red blood cell parameters, neutrophilia, and lymphocytosis and of age on hypokalemia. K E Y W O R D Sblood cell count, blood coagulation tests, chemistry, clinical, dento-alveolar trauma, maxillofacial injuries, urinalysis