A controlled study was carried out on 160 patients of both sexes (age between 39 and 86 years) discharged from the Cardiology Department of the Santa Chiara Hospital, Pisa, with a diagnosis of recent myocardial infarction. L-carnitine was randomly administered to 81 patients at an oral dose of g 4/die for 12 months, in addition to the pharmacological treatment generally used. For the whole period of 12 months, these patients showed, in comparison with the controls, an improvement in heart rate (p < 0.005), systolic arterial pressure (p < 0.005) and diastolic arterial pressure (NS); a decrease of anginal attacks (p < 0.005), of rhythm disorders (NS) and of clinical signs of impaired myocardial contractility (NS), and a clear improvement in the lipid pattern (p < 0.005). The above changes were accompanied by a lower mortality in the treated group (1.2%, p < 0.005), while in the control group there was a mortality of 12.5%. Furthermore, in the control group there was a definite prevalence of deaths caused by reinfarction and sudden death. On the basis of these results, it is concluded that L-carnitine represents an effective treatment in post-infarction ischaemic cardiopathy, since it can improve the clinical evolution of this pathological condition as well as the patient's quality of life and life expectancy.