Conjoined twins are uncommon with reported incidences of 1 in 30,000–200,000 births. They represent a heterogeneous population in regard to location of joint body parts and presence/extent of internal organ fusion. Positioning, airway management, possible presence of cross-circulation, and the fact that 2 patients require anesthesia for each procedure present significant challenges to the anesthesiologist. We report the anesthetic care of a conjoined twin set in which one of the patients presented with tricuspid atresia, d-transposition of the great arteries, and both atrial and ventricular septal defect. A balloon atrial septostomy was performed to allow survival after a separation procedure.