Examination of the patterns of free-radical processes (FRP) and changes of the early screening markers to predict the course of hemorrhagic stroke (HS) and applied pathophysiologically based therapy can be of great practical importance. This study aimed to determine early changes in the parameters of oxidative stress and routine biochemistry blood tests in patients with HS and to assess their relationship with clinical outcome. The effects of early applied cytoflavin were also investigated. The prospective study included 151 patients with HS. Forty-eight percent of patients in the standard conservative therapy were given cytoflavin antioxidant energy therapy from the first day of hospitalization. The neurological status, neuroimaging, biochemical blood tests and FRP were assessed on days 1, 5, 10, and 20 of hospitalization. In patients with HS, an imbalance of all stages of FRP was detected proportionately to the severity of HS. The malondialdehyde concentration above 5.3 μmol/L, the number of leukocytes above 15 800, glucose above 11.9 mmol/L, lactate dehydrogenase above 574 IU/L, and lactate above 2.5 mmol/L, detected on the first day, predetermined a high risk of death. Additional cytoflavin treatment allowed stabilizing the clinical laboratory picture of HS, improved the treatment results, and reduced hospital mortality rate.