Ocular toxoplasmosis is caused by the parasite Toxoplasma gondii. The organism may lead to acute or chronic infection in humans. Humans may acquire the disease by ingestion of the cyst of the parasite in undercooked beef, lamb, pork, or chicken. Other modes of transmission include the ingestion or inhalation of oocysts, by organ transplantation from infected donors, or by transplacental transmission. The systemic illness presents as a flu-like illness with fever, postauricular lymphadenopathy, myalgia, and malaise. Following acute systemic illness, the retina and choroid may become infected by the parasite several weeks to several years after the initial systemic illness.