We report a case of neonatal lupus syndrome (NLS) in an in vitro fertilization induced triplet pregnancy. Echocardiographic signs of myocarditis were evident at the 21st week of gestation (w.g.) in twin I, with a subsequent development of a complete atrioventricular (AV) block at the 25th w.g.; twin III also displayed echocardiographic signs of myocarditis at the same time. Treatment with dexamethasone (4mg/day) was started at the 25th w.g. A complete echocardiographic regression of the myocarditis signs was achieved, while AV block was unaffected. Caesarian section was performed at the 31.5 w.g. after a premature rupture of the membranes. Complete AV block was confirmed in twin I with a heart rate of 51 beats/min that required a pacemaker implant 40 days after. Twin III developed a first-degree AV block that switched to a periodic second-degree block later, while twin II displayed only liver enzyme abnormalities.