Previous studies have demonstrated a relationship between both age and body surface area (BSA) and M-mode echocardiographic measurements of left ventricular, left atrial, and aortic root dimensions and left ventricular wall thickness. We evaluated the relationships between age, BSA, gender and blood pressure, and Doppler aortic and pulmonary artery (PA) flow velocity measurements in 97 adults, aged 21 to 78 years, without clinical evidence of cardiac disease. No significant relationship was found between gender or blood pressure and aortic or PA flow velocity measurements. Aortic peak flow velocity, flow velocity integral, and average acceleration decreased with increasing age (all p less than 0.001), whereas ejection time (corrected for heart rate) increased, and acceleration time did not change. In contrast, there was no relationship between age and Doppler PA flow velocity measurements. Although there was no relationship between BSA and Doppler aortic flow measurements, PA peak flow velocity and average acceleration increased, while acceleration time decreased with increasing BSA (all p less than 0.02). Decreases in aortic peak flow velocity and flow velocity integral may be partly related to known increases in aortic root diameter with aging. The relationship between PA flow velocity measurements and BSA is not readily explained.