Despite the finding of elevated Tricuspid Regurgitant Velocity (TRV) in children below 5 years of age, the prevalence and evolution of Pulmonary Hypertension (PH) in young children with sickle cell disease (SCD) are unclear. In order to identify predictive factors of precocious PH development, SCD children > or =3 years old, at steady state, underwent annual echocardiography and Tissue Doppler Imaging (TDI). Patients receiving chronic transfusion were excluded. Thirty-seven of seventy-five patients were > or =3 years, with measurable TRV. In our young population (mean age 6.2 years) of mainly African, HbS/HbS patients, 8/37 (21.6%) had TRV > or =2.5 m/s, 8% being only 3 years old. Significant correlation was found between precocious TRV elevation and high platelet and reticulocyte counts and frequent acute chest syndromes (ACS). In multivariate analysis, ACS was the only variable predicting TRV > or =2.5 m/s. TDI of the 37 patients showed signs of diastolic dysfunction of the left ventricle. At follow-up all eight patients with high TRV displayed further increase and seven more developed TRV > or =2.5 m/s. PH seems to begin in children earlier than expected. Factors involved in its early onset might be different from the ones causing its development in older children or adults. African children might benefit from early screening and re-assessment once a year.