In recent years, a variety of resorbable plates have been used for craniofacial fractures. The authors report a case of plate infection that occurred more than 1 year after surgery and was difficult to distinguish from a foreign body reaction. A 19-year-old male suffered fractures of the right zygomatic bone, orbital floor, and left maxilla in a motorcycle accident. Reduction was performed using resorbable plates at 7 days after injury. The postoperative course was good. However, the patient presented 396 days after surgery with redness/swelling of the right upper eyelid and right cheek pain. There were no systemic signs of infection such as fever. A foreign body reaction to the plate was suspected. After 1 week, swelling of the patient's upper eyelid was worse, and the remaining resorbable plate was removed via a skin incision. Swelling subsequently extended to the right cheek and upper gingiva, and all plates were removed under general anesthesia on the 418th day after the first operation. The swelling subsided after removal of the plates. Pathological examination revealed neutrophil infiltration and Staphylococcus hominis was detected by bacterial culture, leading to a diagnosis of late-onset plate infection. This coagulase-negative staphylococcus usually causes infection in neonates and immunocompromised individuals. Postoperative complications of resorbable plates include foreign body reaction and infection, which are difficult to differentiate clinically. Removing the foreign body is the principal technique for obvious wound infection. A foreign body reaction with subcutaneous fluid retention is slow to heal. Therefore, early plate removal is also recommended.