The world's surgical experience on the division of craniopagi is reviewed, and a new case is reported. The problems, including ethical considerations, that must be addressed in selecting patients for operation and in preparing for the procedure are discussed in detail. Hemodynamic stability and the problem of intraoperative gravitational distortion of the brain are addressed. The importance of careful planning is stressed. Survival of the 31 craniopagi after operation is discussed in relation to types of junction.