Background: Acute brain injury (ABI) disrupts homeostasis in tissue brain. Inflammation has an important contributory role in the pathogenesis of the disease and blood cell count alteration has been shown. The clinical course is variable, and the factors or markers available for predicting survival or the functional situation of these patients are limited. Aim: The aim of this study was to measure the serum levels of interleukin (IL)-8, transforming growth factor (TGF)-β1 and nitric oxide (NO) in patients with ABI (at days 1, 2, 3 and 7) and to study their relationships to blood cell counts. Methods & results: A total of 25 patients were included in the study and 15 healthy subjects were chosen as a control group. Expression of IL-8 and TGF-β1 and production of NO were higher in ABI patients at each of the time points as compared with the control group. In the case of TGF-β1, the increase at time points 3 and 7 was greater than time points 1 and 2. White blood cells were increased significantly (12130 ± 1372 cells/µl; p < 0.01). A huge decrease in platelet counts was also observed (202 ± 14 cells/µl; p < 0.01). Interestingly, no significant correlation was found between the serum levels of these mediators and blood cell counts (mainly considered leukocytes and platelets). Discussion & conclusion: This study shows dramatic increase in the serum levels of three important mediators involved in inflammation and progression of ABI. We showed that there is no correlation between the serum levels of these mediators, leukocytes and platelets and probably they act independently from each other.