BACKGROUND Liver abscesses caused by Klebsiella pneumoniae associated with dental implant surgery are rare. We report a case of liver abscess and septic pneumonia caused by K. pneumoniae in a patient who developed a peri-implant abscess following dental implant surgery. METHODS The 69-year-old male patient underwent a dental implant surgery on the upper right first premolar 10 days prior to admission, and the toothache and facial swelling worsened 5 days before admission. RESULTS One day before admission, a peri-implant abscess was diagnosed at a local dental clinic, and the patient underwent irrigation and drainage. On the day of admission, the patient visited our dental department and was admitted through the emergency room due to melena. The patient underwent further irrigation and drainage of the peri-implant abscess around the upper right first premolar. A liver abscess in segments 2/3 (3.1 cm) and septic pneumonia were diagnosed, and K. pneumoniae was identified in the blood and sputum cultures. The patient received antibiotic therapy (piperacillin-tazobactam, meropenem, and ceftriaxone, sequentially) without percutaneous drainage of the liver abscess due to the patient's refusal and recovered without complications. The patient was administered ciprofloxacin for 5 months after discharge. One month after admission, the inflammatory maker returned to within reference range. The patient improved with long-term antibiotic treatment alone without drainage of the liver abscess. To our knowledge, this is the first report of a liver abscess caused by K. pneumoniae originating from a peri-implant abscess after dental implant surgery. CONCLUSIONS Clinicians should be aware of the potential occurrence of liver abscesses caused by K. pneumoniae if signs of systemic infection persist along with peri-implant infection after dental implant surgery.