To describe the clinical features, histopathology, treatment, and outcomes of ciliary body medulloepithelioma. Retrospective study. Forty-one patients with medulloepithelioma. Cryotherapy, plaque radiotherapy, external beam radiotherapy, tumor removal by partial lamellar sclerouvectomy (PLSU), or enucleation. Metastasis and death. Of 41 patients with ciliary body medulloepithelioma, the median age at diagnosis was 5 years. The mean tumor basal diameter was 11 mm, and the mean tumor thickness was 7 mm. Related features included secondary glaucoma (n = 18, 44%), iris neovascularization (n = 21, 51%), cataract (n = 19, 46%), lens subluxation (n = 11, 27%), lens coloboma (n = 8, 20%), retrolental neoplastic cyclitic membrane (n = 21, 51%), intratumoral cysts (n = 25, 61%), and extraocular extension (n = 4, 10%). There was systemic association with pleuropulmonary blastoma in 2 cases (5%). Primary tumor treatment included enucleation (n = 21, 60%), tumor removal by PLSU (n = 8, 23%), plaque radiotherapy (n = 3, 9%), external beam radiotherapy (n = 1, 3%), cryotherapy (n = 1, 3%), or palliative chemotherapy (n = 1, 3%). In 1 case, medulloepithelioma was diagnosed histopathologically after inadvertent evisceration for blind painful eye. Subsequent treatment for residual or recurrent tumor in cases treated conservatively/inappropriately (n = 15) was necessary in 7 cases (47%). Histopathology disclosed benign features in 6 cases (20%), malignant features in 24 cases (80%), teratoid features in 11 cases (37%), and nonteratoid features in 19 cases (63%). In the 26 enucleated eyes, other features included retrolental neoplastic cyclitic membrane (n = 18, 69%), neoplastic epiretinal membrane (n = 6, 23%), and persistent hyaloid artery (n = 6, 23%). Systemic metastasis occurred in 3 cases (8%) over a mean follow-up of 49 months, all of whom presented with extrascleral extension of tumor due to mean delay in diagnosis by 39 months. Medulloepithelioma most commonly occurs in children. Systemic association with pleuropulmonary blastoma rarely is found. Patients with extrascleral medulloepithelioma are at risk for metastasis.