Tamoxifen, an oral medication that blocks estrogen activity, is frequently prescribed for the treatment of advanced breast cancer and as an additional therapy following surgical removal of early stage disease. A 45-year-old female with a history of breast carcinoma treated with tamoxifen presented with sudden onset bilateral visual impairment for 4 days. On ocular examination, the patient exhibited optic disc edema with hyperemia and bilateral anterior pathway defects in visual evoked potentials. Magnetic resonance imaging revealed a thickened right optic nerve sheath with patchy enhancement of the left optic nerve sheath. The patient was diagnosed with bilateral optic neuritis and treated with intravenous methylprednisolone, which resulted in significant improvement in visual acuity and resolution of optic disc edema. This case underscores the importance of vigilant ophthalmological monitoring in patients undergoing tamoxifen therapy to facilitate the early detection and management of ocular complications.