Syphilis is a sexually transmitted infection caused by Treponema pallidum. Ocular involvement is rare and diagnosis of ocular syphilis is challenging due to nonspecific symptoms. The diverse manifestation of ocular syphilis occurs as well in secondary as in tertiary syphilis, for it can affect all structures of the eye; corneoscleral, uveal, retinal, and optic nerve inflammation may be observed. We report on a case of ocular syphilis affecting the vitreous body in a 43-year-old healthy male with a 6-month history of diminished visual acuity in the left eye.