Several neuro-ophthalmic manifestations have been reported with coronavirus disease 2019 (COVID-19) infection. However, isolated optic neuritis was infrequently reported in humans with COVID-19. If it occurred, optic neuritis was usually a part of a demyelinating syndrome.In this paper, we report a case of optic neuritis concomitant with an undiagnosed pituitary macroadenoma discovered during active COVID-19 infection. The case was a 33-year-old woman with infertility who was recently found to have a pituitary macroadenoma secreting prolactin. During active COVID-19 infection, the patient developed optic neuritis that responded well to corticosteroids. Brain imaging and hormonal profile negated the presence of any demyelinating disease or pituitary apoplexy.A dilemma of whether optic neuritis occurring concomitantly with pituitary macroadenoma is just a coincidence, or there is an association remains unresolved. Whether COVID-19 infection might precipitate optic neuritis in patients with pituitary macroadenoma or not remains an issue to be answered by observing data from future case reports about similar findings.Optic neuritis in concomitant with pituitary macroadenoma following COVID-19 infection represents a dilemma of whether the visual symptoms are attributed to the tumor or COVID-19 infection.