INTRODUCTION: mild head trauma (MHT) is defined as a transient neurological deficit after trauma with a history of impairment or loss of consciousness lasting less than 15 min and/or posttraumatic amnesia, and a Glasgow Coma Scale between 13 and 15 on hospital admission. We evaluated 50 MHT patients 18 months after the trauma, addressing signs and symptoms of post-concussion syndrome, quality of life and the presence of anxiety and depression. We correlate those findings with the S100B protein levels and cranial CT scan performed at hospital admission after the trauma. METHOD: patients were asked to fill out questionnaires to assess quality of life (SF36), anxiety and depression (HADS), and signs and symptoms of post-concussion syndrome. For the control group, we asked the patient's household members, who had no history of head trauma of any type, to answer the same questionnaires for comparison. RESULTS: total quality of life index for patients with MHT was 58.16 (+/-5), lower than the 73.47 (+/-4) presented by the control group. Twenty patients (55.2%) and four (11.1%) controls were depressed. Seventeen patients (47.2%) presented anxiety, whereas only eight (22.2%) controls were considered anxious. Victims of MHT complained more frequently of loss of balance, dry mouth, pain in the arms, loss of memory and dizziness than their respective controls (p<0.05). We found no correlation between the presence of these signs and symptoms, quality of life, presence of anxiety and depression with S100B protein levels or with presence of injury in the cranial CT performed at hospital admission. CONCLUSION: MHT is associated with a higher incidence of post-concussion syndrome symptoms, lower quality of life and anxiety than their respective controls even 18 months after the trauma.