The purpose of this study was to investigate the effect of coronectomy on postoperative quality of life in older adults. Coronectomy is an alternative to complete surgical removal of a mandibular third molar that lies close to the inferior alveolar nerve. This prospective study included patients >60 years old who had an indication for coronectomy of a mandibular third molar. Patients were asked to complete the Dutch version of the Oral Health Impact Profile-14 (OHIP-14) daily during the first postoperative week. Postoperative pain, swelling, limited mouth opening, chewing ability and infection were also recorded. Furthermore, the effect of the impaction pattern, state of eruption, presence of preoperative pathology, patient health status according to the American Society of Anaesthesiologists score, gender, smoking on the postoperative OHIP-14 and pain scores were investigated. Thirty patients (16 males, 14 females) with a mean age of 71.2 (SD 8.3, range 60-91) years were included in the study. OHIP-14 and pain scores were highest on the first postoperative day and gradually declined during the first postoperative week. Patients who underwent coronectomy of a fully impacted mandibular third molar had significantly higher OHIP-14 scores on the first postoperative day than those who underwent coronectomy on a (partially) erupted mandibular third molar. We did not observe any postoperative complications up to 1 year after the surgery. Mandibular third molar coronectomy seems to present a valid treatment option in older adults.