We evaluated the risk of pulmonary hypertension (PH) by measuring the velocity of the tricuspid regurgitation jet velocity (TRV) on echocardiography and the associations among the TRV, ferritin, and history of splenectomy in children with β thalassemia major (TM). In total, 85 children with TM were examined with continuous Doppler flow. Patients with an abnormal TRV (>2.5 m/s) were grouped into those with a TRV of 2.5 to 2.9 m/s and TRV>2.9 m/s. A TRV of >2.5 m/s was identified in 72; 31 (36%) of these patients had a TRV of >2.9 m/s, suggesting a risk for significant PH. The ferritin concentration was significantly higher in patients with a TRV of >2.9 m/s and showed a positive correlation with a TRV. The TRV was significantly correlated with markers of diastolic function: the tricuspid peak early diastolic wave (E) was higher in patients with a TRV of >2.9 m/s and showed a significant correlation with the TRV (R=0.315). The ratio of the TRV over the velocity-time integral (VTI) at the right ventricular outflow tract (TRV/VTI RVOT), which is correlated with the pulmonary vascular resistance, was higher in patients with a TRV of >2.9 m/s. In total, 27 patients had splenectomy. Splenectomized patients had a higher TRV and splenectomy was correlated with the TRV (R=−0.221). A risk of PH as defined by a TRV of >2.9 m/s was common in our patients with TM. Screening with Doppler flow indices on echocardiography can detect PH in early stages.