A single dose of 60 mg trimetazidine (the normal daily dose) improved exercise capacity in angina pectoris, as reflected by an increase in the duration of exercise, total work performed, and improvement in ECG signs of ischaemia. All these effects occurred without any detectable chronotropic or vasomotor effect. The importance of this study is to demonstrate that these beneficial effects, already well-recognized after chronic administration of 20 mg three times a day, also occur after a single administration equivalent to the normal daily dose.