Abstract: Traumatic cataract is relatively common in clinical practice. Typically, non-metallic foreign bodies entering the eye do not cause intraocular reactions, manifesting only as traumatic cataract, while metal foreign bodies entering the eye are more likely to cause complications. Foreign bodies entering the eye can be detected through ophthalmic examination or found during cataract surgery. However, a very small number of patients may experience missed diagnosis in clinical practice. This article reported a case of traumatic cataract with disappearance of intraocular metal foreign body, presenting with a history and signs of ocular trauma and foreign body entry into the eye, but no foreign body was found before, during or after surgery. The reasons for the disappearance of the metal foreign body were also analyzed.