This paper reports an implant periapical lesion (IPL) with a previously unreported etiology. The presence of an osteolytic area around the apex and around the middle portion of a stable Straumann hollow-screw implant was found on periapical radiographs 3.5 years after implant placement. Case management involved curettage of the soft tissue surrounding the implant apex as well as resection of the nonosseointegrated portion of the implant. Histopathologic examination revealed a connective fibrous tissue containing a dense chronic inflammatory infiltrate with a foreign-body material. Polarized light microscopy and Fourier transform infrared microspectroscopy identified the foreign-body material as starch particles. Etiology of this IPL was thus related to a foreign-body reaction to starch particles. This exogenous contamination probably originated from starch-coated gloves during the surgical procedure. This case report suggests that IPL may successfully be treated by debridement and implant resection instead of implant removal. Peri-implant apical soft tissue should be systematically submitted for histopathologic examination. Keywords: apical peri-implantitis, dental implants, granuloma, implant failure, radiolucency, starch