Bioactive sphingolipids play important role in regulation of the function of the cardiomyocytes. There are no data available on metabolism of the sphingolipids in the heart under increased work-load produced by tachycardia. The aim of the present study was to examine effect of tachycardia on the level of the principal bioactive sphingolipids in the left and right ventricles. The experiments were carried out on male Wistar rats. After anesthesia, two electrodes were administered into the right common jugular vein so that their tips were placed at the vein's aperture. The resting heart rate was 355 ± 24/min and the rate of stimulation was 600/min. EKG was continuously monitored. The stimulation time was 30 and 60 min. Thereafter, blood from the abdominal aorta and samples of the left and right ventricle were taken. The following bioactive sphingolipids were quantified by means of high performance liquid chromatography: sphinganine, ceramide, sphingosine, sphingosine-1-phosphate and sphinganine-1-phosphate. In the left ventricle, 30 and 60 min tachycardia elevated the level of sphingosine, reduced the level of sphingosine-1-phosphate and sphinganine-1-phosphate. The level of ceramide was reduced only after 60 min. In the right ventricle, 60 min pacing resulted in elevation in the level of sphingosine and sphinganine and reduction in the level of other compounds studied. It is concluded that tachycardia induces changes in metabolism of bioactive sphingolipids in each ventricle. The changes may affect cardiomyocyte functions. Also, differences in sphingolipid metabolism between both ventricles are reported.