To determine pulmonary artery variations and other associated cardiac defects in patients with Tetralogy of Fallot (TOF). Cross-sectional, descriptive study. The Children's Hospital and the Institute of Child Health, Lahore, from April 2006 to October 2007. All patients with TOF, who underwent cardiac catheterization during this period, were included. Standard cine-angiograms were recorded and pulmonary artery sizing was done using z-scoring. A total of 216 patients with TOF were catheterized. Pulmonary Artery (PA) abnormalities were present in 84 (38.9%) patients. The commonest abnormality was isolated Left Pulmonary Artery (LPA) stenosis (n=27, 32.14%) followed by isolated hypoplasia of Main Pulmonary Artery (MPA) (n=18, 21.43%) and supra-valvular stenosis in (n=11, 13.1%) patients. LPA was absent in one patient, while 2 patients had both absent right and left PA with segmental branch pulmonary arteries originating directly from MPA. Associated cardiac lesions included right aortic arch in 34 (15%), additional muscular VSD vary in 13 (5.5%), Patent Ductus Arteriosus (PDA) in 11 (6%) and Major Aortopulmonary Collateral Arteries (MAPCA) in 2 (1.9%) patients. Significant coronary artery abnormality was present in 10 (4.6%) children. Pulmonary artery abnormalities were present in 38.9% of patients with TOF. Isolated LPA origin stenosis and MPA hypoplasia were the most common abnormalities. Significant associated cardiac lesions were present in one-third of the patients and included PDA, additional muscular VSD, coronary artery abnormalities and MAPCA.