Retinoblastomas were misdiagnosed as primary ocular inflammations without suspicion of neoplasm in 6.6% of 618 cases and as disease other than ocular inflammation in 8.3%—a total, therefore, of 14.9% misdiagnosed. Misdiagnosis and subsequent delay in therapy appeared to result in a markedly increased mortality in those cases. Intraocular retinoblastomas must be considered in the differential diagnosis of ocular inflammations of childhood.