Intraocular medulloepithelioma is an uncommon embryonic tumor. Its diagnosis is based on the clinical findings such as the presence of a ciliary body tumor, intratumoral cysts confirmed by ultrasound, iris neovascularization, corectopia, uveal ectropion and retrolental membrane. Diagnosis is confirmed by the pathology report. We present the case of a malignant teratoid medulloepithelioma confined to the eyeball in a 1-year-old patient. Metastasis evaluation was negative, so she remained under close ophthalmological and oncological surveillance after enucleation. Compared with other intraocular tumors, medulloepithelioma is more likely to develop secondary glaucoma, a complication that has been described in 60% of these tumors, probably secondary to iris neovascularization. In pediatric patients who attend consultation due to buphthalmos and congenital glaucoma under evaluation, it is important to exclude intraocular tumors through imaging studies for timely diagnosis and treatment. Retinoblastoma, rhabdomyosarcoma, neuroblastoma, vascular malformations, hematic cysts, glioneuroma and persistent hyperplastic primary vitreous, should be considered in the differential diagnosis. Malignant teratoid medulloepithelioma has a risk of mortality of 10%, related to intra and extracranial dissemination (mainly to regional lymph nodes)