OBJECTIVE: Whether oral health care during the perioperative period can lead to a better outcome after heart valve surgery has not been adequately elucidated. We examined the effects of perioperative oral care on postoperative inflammation response in patients who underwent heart valve surgery. MATERIALS AND METHODS: In this retrospective cohort study, 223 patients scheduled for single valve heart surgery were divided into the oral care, who underwent professional teeth cleaning or scaling within 3 days prior to surgery, and also following surgery at least twice a week (n = 111), and non-oral care (n = 112) groups. After propensity score matching, records of both groups (80:80) were examined after surgery to evaluate inflammation markers (white blood cell count [WBC], neutrophil/white blood cell ratio [NWR], C-reactive protein [CRP] level, body temperature [BT]). RESULTS: WBC, NWR, CRP level, and BT were increased in both groups the day following surgery. Thereafter, CRP level, WBC, NWR, and BT on various days after surgery in the oral care group showed greater decreases as compared to the non-oral care group. CONCLUSIONS: Perioperative oral health care can decrease postoperative inflammation in patients undergoing heart valve surgery and may be important to ensure a better outcome in those patients.