The results of controlled, retrospective clinical investigation of applying cell transplantation (CT) therapy in 38 severely head-injured patients are presented. The patients initially were in state of coma (Glasgow coma scale score 3–7), owing to their traumatic brain injuries. Cells prepared from fetal nervous and hematopoietic tissues were grafted subarachnoidally via lumbar puncture. The control group consisted of 38 patients and was clinically comparable with the trial one. From the results obtained it appears that CT treatment promoted both wakening consciousness of the patients and their following neurological rehabilitation. A death-rate in the trial and control group was 5% (two cases) and 45% (17 cases), respectively. According to a Glasgow scale, favorable (good + satisfactory) outcomes of a disease were noted in 33 (87%) cell-grafted and only in 15 (39%) control patients. Statistical analysis revealed that CT treatment generally improved the outcomes by 2.5-fold. No serious complications of CT therapy were noted. The results point out a possible rationality of applying CT therapy in severely head-injured patients as early as within acute period of a disease.