Impairment of relaxation, the early phase of ventricular diastole is the first stage of heart diastolic dysfunction. Left ventricular diastolic function can be determined noninvasively by Echo- Doppler – derived mitral valve flow velocities. The addition of pulmonary venous flow pattern enables more accurate assessment of left ventricle diastolic function. The role of the right ventricle in haemodynamic function of the heart is now emphasized. The right ventricle diastolic function can be assess by recording the Doppler tricuspid valve flow pattern. Impaired LV diastolic function usually precedes systolic dysfunction and may cause clinical signs of congestive heart failure. Cigarette smoking is one of the major risk factors for cardiovascular diseases. The aim of the study was to assess left and right ventricular diastolic function in healthy, young and slim smokers before and after smoking one cigarette.