Retinoblastoma is the most common childhood intraocular cancer. It originates from a mutation of the retinoblastoma (RB1) gene, a tumour-suppressor gene. Infants are usually diagnosed through an incidental finding of leukocoria. The disease is classified by size, location and number of tumours and it is used to determine treatment. Management includes surgery, radiotherapy, photocoagulation and chemotherapy. Early diagnosis and treatment is key to preserving vision and therefore a thorough understanding of the condition is important.