A 25-year-old man presented with a unilateral retinal detachment, and an ipsilateral preretinal mass; ultrasonographic findings included a high-reflective peripheral mass and a retinal fold. A presumptive diagnosis of a peripheral toxocara granuloma was entertained. We performed a 360 degree circumferential scleral buckle and a conventional vitrectomy via the pars plana. Histologic examination of the mass defined a central non-metallic foreign body surrounded by fibrous tissue.An intraocular non-metallic foreign body, surrounded by a fibrous capsule and feeding and draining blood vessels, can mimic the characteristics of a peripheral toxocara granuloma, and the differential diagnosis has to be kept in mind.