OBJECTIVE There are few publications which relate the injury severity score (ISS) to the thoracolumbar burst fractures. For that reason and for the frequency in which they occur, we have evaluated the severity of the trauma in these patients. METHODS We have evaluated 190 burst fractures in the spinal cord according to Denis, using the codes of Abbreviated Injury Scales (AIS) for the calculation of the ISS, which uses the three parts of the human body with major severity. These lesions are a squared number and the results are summed up. RESULTS Among 190 cases evaluated, the median value of the ISS was 13 and the average was 14,4. Males presented a higher ISS than females. The young adult patients presented an average and a median value of the ISS higher than the old patients. The higher the ISS is, the longer the hospitalization period is, except for the patients with the ISS over 35. The fractures in thoracic level show the ISS higher than the rest. The ISS is directly related to surgical treatment and mortality. CONCLUSIONS The ISS values which were found show that a less severe trauma can cause a burst thoracic or lumbar spinal cord fracture. The value of the ISS has not shown correlation to the sex and the fracture level, but it is proportional to the hospitalization period, the surgical treatment and the mortality rate. This result shows a value which is inversely proportional to the age of the patients.