Interferon alia and its related compounds have been used for more than 10 years in the treatment of a number of conditions including viral illnesses, childhood hemangiomas, various cancers, and leukemia. The potential applications for this class of medication continue to grow. The use of interferon alia in experimental protocols has also increased, thus making it more likely that new indications will be discovered. It is probable that primary care physicians will be called on to initiate therapy or will see patients being treated with interferon in their practice. We report the development of interferon-related retinopathy in a 43-year-old man while he was receiving experimental treatment with interferon alfa for hepatitis B virus and hepatitis C virus infection. The vision loss was acute and only partially reversible. Interferon, its mechanism of action, and the past literature are briefly discussed.