In order to compare the efficacy of 10 antihypoxic agents, 550 patients with macrofocal myocardial infarction were examined. Of these patients, 235 underwent conventional treatment, while 315 patients, divided into representative groups of 25 to 40 patients, received, for first two to five days of disease, additional doses of one of the following antihypoxic agents: amtizol (i.v., 2 mg/kg·d to 15 mg/kg·d), riboxin (i.v., 3 mg/kg·d to 6 mg/kg·d), oliphen (i.v., 2 mg/kg·d to 3 mg/kg·d), pyracetam (i.v., 15 mg/kg·d to 150 mg/kg·d), cytochrome C (i.v. and i.m., 0.15 mg/kg·d to 0.30 mg/kg·d), meldronate (i.v., 500 mg/d), lithium oxybutyrate (i.m., 10 mg/kg·d to 15 mg/kg·d) and aspisol (i.v., 12 mg/kg·d to 15 mg/kg·d) or underwent standard hyperbaric oxygenation procedures. Antihypoxic agent administration was accompanied with a decrease in mortality rate, from 23.0% to 9.0%, and a change in the pattern of mortality. Under the influence of antihypoxic agents, significantly more rapid normalization of blood enzyme levels and decrease of lymphopenia were observed (both these parameters taken as prognostic ones). Judging by clinical data and changes in laboratory parameters, amtizol, lithium oxybutyrate, pyracetam and riboxin proved to be the most efficient antihypoxic agents at given doses. Meldronate and oliphen appeared to be less effective. Cytochrome C, solcoseryl and aspisol produced only slight protective effects. Hyperbaric oxygenation did not improve laboratory parameters and resulted in an increased incidence of complications. It seems expedient to include active antihypoxic agents in standard therapy for complicated forms of acute myocardial infarction.