A large series of cases of malignant choroidal melanoma has been reviewed. Certain risk factors have been related to prognosis by means of actuarial life tables. With information from these tables to calculate mortality rates graphs were drawn for various risk factors to demonstrate the differing pattern in tumours of varying size, degree of pigment, position of anterior border, etc. Further, a discriminant analysis was carried out in relation to differing cell types of tumour. It was concluded that tumour size overall was most important for assessing prognosis, and for small tumours the type of treatment seems not to influence survival. The presence of an early mortality peak is found, as suggested in other series, but a second peak is also present. A possible cause of this later peak is suggested.