Background Prediction of mortality in a patient with head trauma is essential. In this study, the effect of mean platelet volume (MPV) on the mortality rate of patients with severe head trauma was studied. Material and methods The relationship between mortality and mean platelet volumes of patient with cranial trauma was retrospectively analyzed. Results 43 patients with head trauma were admitted to the intensive care unit during the study period. While 17 patients died (Group I), 26 patients survived (Group II). Cox regression analysis showed that late MPV (at exitus or discharged date), WBC at admission, and age increase the mortality rate 1,770, 1,202, 1,052 times, respectively. Conclusions The present study shows that MPV may be a useful predictor of mortality in patients with severe head trauma.