AbstractIn this communication we have examined the acute haemodynamic effects of two flavonoids with different electrophysiological characteristics, rhoifolin and vitexin, in anaesthetized dogs. The following haemodynamic parameters: mean aortic pressure, left ventricular systolic pressure, left ventricular end‐diastolic pressure, and its first derivative, mean arterial and pulmonary capillary wedge pressure, right atrial pressure and heart rate were measured. The results obtained have shown that rhoifolin and vitexin caused a decrease of mean aortic pressure, of the arterial and pulmonary capillary pressure and of heart rate. Differences in the left ventricular performance index of the two flavonoids were also noted.