['This study was aimed to assess whether serum S100B levels at emergency department admission can be used to omit unnecessary computed tomography (CT) in patients with minor head injury (MHI).', 'Sixty consecutive patients with recent MHI were included in this study. Serum S100B measurement and CT scanning were performed in all patients within 3h from head injury.', 'A positive CT scan was present in 20 out of 60 subjects. Significantly higher values of protein S100B were found in CT positive than in CT negative patients (1.35 versus 0.48 μg/L; p<0.001). The area under the ROC curve for protein S100B was highly significant (AUC 0.80; p<0.001) and a S100B cut-off value of 0.38 μg/L displayed 100% sensitivity and 58% specificity.'] Do serum levels of protein S100B predict intracranial lesions in mild head injury?