Four patients are discussed who underwent hemodialysis and developed anterior ischemic optic neuropathy (AION). Three patients had been treated by hemodialysis for several years. One patient developed bilateral optic neuropathy after the first hemodialysis session, So far, only four hemodialysis patients with bilateral AION have been reported in the literature. One of these reported patients had optic disc drusen; another suffered from severe blood loss. It is suggested that the ischemic optic neuropathy in our four patients may have been caused by low blood pressure, which was very difficult to regulate in these patients, Three of our patients developed bilateral optic neuropathy, the second eye shortly after the first. One patient had unilateral AION, which remained unilateral for four years.