None of the reports of delayed infection mentioned a latent period exceeding 13 months. we report an infection that developed 18 months after implantation of an absorbable plate. A 16-year-old adolescent girl had undergone reduction and fixation with an absorbable plate for Lefort I and zygomaticomaxillary complex fractures 18 months prior at our hospital. In her most recent hospital visit as an outpatient, abscess was observed in periocular area. Computed tomography revealed sinusitis with an abscess above the infraorbital rim. Wound culture yielded methicillin-resistant Staphylococcus aureus . Despite conservative treatments, wound state did not improve. Therefore, our department decided to perform surgery. Absorbable plate had been mostly absorbed but remained a bit. Bony depression of infraorbital rim and mucosal exposure of maxillary sinus anterior wall were observed. After the surgery, the patient recovered. We believe that the reason the wound infection and sinusitis manifested at the same time is because of several factor such as alcohol abuse, smoking, and mucosal exposure of maxillary sinus anterior wall. Absorbable plate takes 9 months to 3 years to be completely absorbed, thus we suggest studies with a follow-up of at least 3 years be undertaken to determine the outcomes of patients with many risk factors.