Computed Tomography (CT) is a diagnostic imaging modality giving higher patient dose in comparison with other radiological procedures, so the calculation of patient dose in CT exams is very important. CT improved the diagnosis many of the diseases. The increasing use of CT in the Sudan in recent years is what has to think in the attempt to reduce the exposure of the patient and that the risks known to the X-ray. This study aimed to measure the radiation dose and estimating the risks resulting from exposure to X-rays during the imaging by CT scan. A total of 130 patients were examined in two hospitals using two spiral CT scans 64 slices (Alamal National and Alzaytouna specialist hospitals in the period (March 2011-June 2011). The average age of the samples was 45±18 years. The mean effective dose for Al-amal National hospital was 17.4±12.7 mSv, 22.9±14.3 mSv and 2.4±0.9 mSv for the chest, abdomen and brain examinations, respectively. The mean effective doses for Al-Zaytouna specialist hospital were 26.3±7.8 mSv, 47.6±33.0 mSv, and 3.7±1.5 mSv for the chest, abdomen and brain, respectively.