Endoscopic treatment of suprasellar arachnoid cysts is now the treatment of choice. By marsupializing the roof of the cyst the condition can be cured. The perceived necessity to open both the roof and the floor is called into question by this paper. Three cases of suprasellar arachnoid cyst are described all of which have had successful marsupialisation of the cysts by flexible neuroendoscopy Flexible neuroendoscopic marsupialization of the cyst by widely opening the cyst roof only is described. This is compared with the other techniques, and also the endoscopic technique involving opening both the roof and the floor of the cyst, a more difficult and potentially dangerous method. Successful treatment of this condition is achieved by marsupialization of only the roof of the cyst. This is a much safer procedure, and has resulted in a resolution of signs and symptoms in the cases described followed-up between 24 and 28 months from the procedure.