A 21-year-old male patient operated for esotropia 10 months ago presented to our clinic with the complaint of swelling and stinging on the right upper eyelid. Physical examination revealed a yellowish foreign body (cellulose sponge) at the lateral fornix, which induced localized papillary reaction on eyelid conjunctiva and vascularization on bulbar conjunctiva. The foreign body was removed and medical treatment was initiated. Foreign body surrounded with giant cells was reported on histopathologic examination. Although cellulose sponge is not routinely used in strabismus surgery, it may be used especially in some hemorrhagic cases. It is important to control the field and to remove all materials from the eye at the end of the surgery.