Displacement of dental implants into the maxillary sinus is not an uncommon event in implant dentistry and may lead to serious complications, such as sinusitis. To avoid systemic problems, performing the removal of the foreign body as soon as possible is suggested. Despite the fact that early implants dislocation has been reported several times, late migration into maxillary sinus has been described by just a few studies. The purpose of this study was to report a rare case of dental implant migration into maxillary sinus after 12 years of function. A 61-year-old woman came to our attention in June 2015 after being visited by an otolaryngologist and being diagnosed with sinusitis and presence of a foreign body into the right maxillary sinus. A panoramic radiograph and a CT scan showed the migration of dental implant sited in 1.6 positions into the maxillary sinus. The implant was removed following a Caldwell-Luc procedure under local anesthesia. Postoperative course was uncomplicated and the patient reported no symptoms of sinusitis after 12 months of follow-up.