Background and aim: Hemothorax is a critical issue in patients with chest trauma. It should be diagnosed quickly and accurately. The study's aim was to define the potential role of pleural fluid (PF) attenuation value determined on computerized tomography (CT) for the diagnosis of traumatic hemothorax. Methods: From 01.07.2011 to 01.07.2016, patients with PF detected on CT with tube thoracostomy were reviewed. On CT sections, PF attenuation values taken from levels where pleural fluid had the most intense appearance were measured as Hounsfield Units (HU). The relationship between HU values and chest traumatic findings, macroscopic discharge diagnosis, peripheral blood Hb and Htc levels and CT protocol were investigated. Results: Thirty eight cases were reviewed in the study group. All PF HU values were determined to be more than 20.0 HU. PF attenuation values were more than 35 HU in 71.1% (n:27) of the cases and between 20.0 and 34.9 for 28.9% (n:11). In the subgroup with hemorrhagic fluid drained from the thoracic cavity, HU values were often higher than 35. For the sub-groups with and without coexisting traumatic findings, there was no statistically significant difference in terms of PF density being below or above 35 HU. No statistically significant correlation was detected between PF HU values and age, peripheral blood Hb and Htc values. Conclusion: For thorax trauma cases, PF attenuation values were between 20.0 to 34.9 HU, and more than 35 HU. Patients with acute trauma who have PF with attenuation value below 35 HU should be considered as hemothorax primarily, even with no coexisting traumatic findings on CT scans.