Human twins have always been of special interest to pediatricians and surgeons concerned with the congenital malformations. Thoracopagus twins, the most common variety of conjoined twin (75%) have in 90% of cases common pericardial sac for both twins. The previous attitude of considering this problem as rare medical curiosity has changed to that of a challenging congenital anomaly to be assessed and treated if possible. Thoracopagus twin survival depends on the site of union of the twins and the resultant fusion of their vital organs. A case of thoracopagus male twins, delivered by caesarean section on 37 weeks of gestation is presented here. The twin died after 24 hours of severe respiratory distress and acidosis. The twin was studied with a particular interest in the cardiovascular system, as it is one of the vital organs which influences the twin survival after successful separation. The twin shared a common pericardial sac and a shared heart. The heart exhibited 2 atrial chambers, placed caudally, each possessing 2 auricular appendages. The fused ventricle was placed cranially and consisted of 2 chambers and two aortic outlets for the two twins at its lateral end, respectively. These findings of the cardiovascular system arising out of the cardiac anlage, has been reported but the present case exhibited unique features. Furthermore, the mode of conjuction, as the degree of fusion laterally or in a facing position seems difficult to interpret in the present case and therefore its suggested that it could be the incomplete fission which may be responsible for the complexity of the cardiac morphology.