We describe a 4-year-old girl with subnormal visual acuity due to a bilateral retinopathy. The child had a history of encephalitis following MMR vaccination. Temporary retinopathy associated with measles, mumps, and rubella (MMR) vaccination has been described . Recently an idiopathic CD4+ T lymphocytopenia in the child was diagnosed. This cellular immunodeficiency supports our hypothesis of measles retinopathy after vaccination of an immuno-deficient child.