Of 500 consecutive patients referred to the Ocular Oncology Service at Wills Eye Hospital with the diagnosis of possible retinoblastoma, 288 (58%) were found on clinical evaluation to have retinoblastoma and 212 (42%) had lesions that simulated retinoblastoma. A total of 23 different conditions accounted for the 212 pseudoretinoblastomas. Three most common pseudoretinoblastomas were: persistent hyperplastic primary vitreous (28%), Coats' disease (16%), and presumed ocular toxocariasis (16%). Congenital cataract and retinopathy of prematurity accounted for a much lower percent of pseudoretinoblastomas in this series as compared to a previously reported series. The pertinent clinical features that serve to differentiate these simulating lesions from retinoblastoma are reviewed.