This study presents 18 years experience (1987 to 2005) of balloon atrial septostomy in patients with d-transposition of the great arteries. Fortyfour patients underwent this procedure, under echocardiographic (Group A, n = 19) and fluoroscopic guidance (Group B, n = 25). The atrial septal defect size and oxygen saturation, before and after the procedure were compared in all as well as in Groups A and B. The atrial septal defect and oxygen saturation increased in all; from means of 2.3 ± 0.6 mm, 48 ± 8% to 4.9 ± 1.3 mm and 72 ± 16.3% after the procedure with statistical significance. Both variables increased in the two groups independently with statistical significance. Transient arrhythmias were encountered in 3 patients and balloon ruptured in one, without any sequel. One had respiratory arrest after morphine administration and required temporary intubation. One patient died due to cardiac tamponade and another due to hepatic vein perforation. Two late presenters expired due to persistent metabolic acidosis even after successful procedure. Therefore, this concludes that balloon atrial septostomy is a safe, effective and life saving palliation, and serves as a bridge for surgical intervention. It is equally effective under fluoroscopic and echocardiograph monitoring.