Background & Objectives: Delayd post-traumatic intracranial hemorrhage (DTICH) is a kind of brain hemorrhage which occurs after the first six hours of the head trauma, and is not detected in the initial CT Scan taken from the patient in the first 6 hours after the trauma. As DTICH is one of the most important factors in occurance of secondary brain injuries in patients with head trauma, its early diagnosis and treatment could significantly decrease mortality and morbidity of these patientes. This diagnosis is a contraindication to anti-coagulant therapy. This study was conducted to determine the frequency of factors associated with DTICH incidence.

 Methods: This was a case-control study conducted in Semnan trauma center. In this research all the patients with head trauma who referred to Emdad hospital between 2002 and 2004 were studied and the data about the delayed post-traumatic intracranial hemorraege (20 cases) were included. Then, beside determining the incidence of DTICH in the patients with hemorrhage, some risk factors such as headache, contusion, reduction level of conciousness, skull fracture and impact intensity to the head were compared with a control group (40 cases) who had head trauma without primary or delayed hemorrhage. The groups were age and sex-matched. The data were analyzed using Chi-aquare and computing odds ratio.

 Results: This study showed that the frequency of DTICH was 10.6%. There was a meaningful relationship between DTICH and skull fracture, reduction of conciousness level, contusion and impact intensity. But, there was no meaningful relationship between DTICH and intractable headache.

 Conclusions: The results indicated that cases such as skull fracture, contusion, impact intensity and findings such as the reduction of consciousness in patients with head trauma (with no hemorrhage in the first CT scan), can be the risk factors for DTICH.