Retinoblastoma is an intriguing subject because of the difficulty of early diagnosis, the fearful penalty for delay in treatment, the question of hereditary transmission and the implications of birth control in the affected families. For these and other reasons, the subject of retinoblastoma is presented in the clinical form of 6 case histories, with a description of the ocular signs which led to enucleation in 5 cases and in the sixth, to the unmistakable diagnosis of angiomatosis. Considering the frequency with which an acute inflammatory reaction leaves a yellow pupillary reflex, which is recognized as the primary sign of retinoblastoma, it is no wonder that eyes are sacrificed; yet, as shown in case 1, the malignant disease may be ushered in by acute congestion of the bulbar conjunctiva, more suggestive of an inflammatory than of a malignant process. REPORT OF CASES Case 1. —When J. K. was 3 years old