The purpose of this article is to report a case of an asymptomatic intralenticular metallic foreign body that was retained for 6 months. A 66-year-old male visited our ophthalmology department because of decreased visual acuity in his left eye 6 months after he suffered ocular trauma while mowing. He had not been treated because he did not experience any discomfort. His corrected visual acuity was 0.4. Central corneal opacity, an intralenticular metallic foreign body, and an intact posterior capsule were observed on slit lamp examination. Phacoemulsification with posterior chamber lens implantation and simultaneous removal of the intralenticular foreign body was performed. Seventeen days after the operation, his corrected visual acuity was 1.0, the intraocular lens was well-seated, and there was no intraocular inflammation. In this case report, a patient was found to have an intralenticular metallic foreign body retained for 6 months. During this time he did not experience any ocular dysfunction due to the foreign body. Mowing accidents are common in Korea. Despite the absence of symptoms, patients reporting a history of lawn mowing should be thoroughly examined.