Serous detachment of the macula is a well-known complication in patients with an optic nerve pit. Despite the many descriptions of this condition and possible treatment options, the long-term natural history is not well known. The authors identified 15 eyes of 15 consecutive patients seen over 21 years who were diagnosed with a serous detachment of the macula arising from an optic nerve pit. Average length of follow-up was 9 years. Twelve eyes lost three or more lines of vision, two eyes remained unchanged, and only one eye improved. All of the 12 eyes losing three or more lines of vision experienced this decrease within the first 6 months of follow-up. Although only two patients had a visual acuity of 20/200 or less initially, 12 of 15 patients had a visual acuity of 20/200 or less at the time of their last examination. The appearance of the macula at last examination included cystic changes of the neurosensory retina, full-thickness hole formation, retinal pigment epithelial mottling, and lamellar hole formation in the outer retinal layer. The long-term visual prognosis in patients with optic nerve pit and untreated serous retinal detachment of the macula is poor, and visual loss occurs within 6 months of the serous detachment.