The unroofed coronary sinus syndrome is a spectrum of cardiac anomalies in which part or all the common wall between the coronary sinus and the left atrium is absent. This defect is part of a developmental complex which includes absence of the coronary sinus and termination of a persistent left superior vena cava in the left atrium. Recognition of this complex is important so that interruption or diversion of the left superior vena cava may be done to prevent subsequent central nervous system complications. Surgical correction uses an intraatrial baffle to divert flow from the left superior vena cava to right atrium and to close the atrial septal defect. This report describes a 7 years old female patient in whom the left superior vena cava was identified preoperatively and the complex [unroofed coronary sinus syndrome, common atrium, mitral valve cleft] recognized at the time of operation. Surgical correction, following repair of cleft mitral valve, utilized a Dacron patch baffle to route the left caval blood to the right atrium and included closure of the atrial septal defect