Atrioventricular septal defect (AVSD) is abnormal development ofthe atrioventricular valves and the septum between the atrial andventricular chambers. Pulmonary hypertension (PH) complicates thecourse of AVSD. Aim of the study to detect the risk factors of PH.Clinical examination and investigations were done for 50 patients withAVSD . we found that risk factors of PH are size of VSD,AVSD and AVvalve regurgitation while the risk factor of pulmonary vascular disease(PVD) is size of VSD.