Retinoblastoma is a curable intraocular malignancy in children. However, in clinical practice, retinoblastoma can sometimes be misdiagnosed and mismanaged, leading to extraocular extension and even death. In this report, a series of 3 cases are related that emphasize the conditions and consequences resulting from misdiagnosis and mismanagement of retinoblastoma. The clinical features, imaging findings, histopatholigical examination, and management in 3 case reports of children with misdiagnosed retinoblastoma are presented. Two of the cases received pars plana vitrectomy after being misdiagnosed with Coats disease or ocular blunt trauma, whereas the third case received evisceration after being misdiagnosed with suppurative endophthalmitis. When the diagnosis of retinoblastoma had been confirmed after a second surgery was performed in our hospital, only 2 of the cases received adjuvant orbital radiotherapy. All 3 cases died of systemic tumor metastases. Intraocular surgical procedures should be avoided in any equivocal case until the possibility of latent retinoblastoma is eliminated.We strongly recommend that early enucleation be executed as soon as possible followed by postoperative adjuvant therapy under conditions wherein an intraocular surgery was inadvertently performed in an eye with retinoblastoma.