Two patients seropositive for the human immunodeficiency virus (HIV) developed bilateral optic neuropathies. Evaluations failed to identify an infectious or neoplastic etiology. Both patients improved, one in temporal relation to treatment with azidothymidine (AZT), the other during oral steroid therapy. Optic neuropathy in HIV-positive patients does not necessarily carry a poor prognosis even when a treatable cause is not found. A role for primary HIV infection in the pathogenesis remains speculative.