A BSTRACT The perio-endo lesions confront the clinician as far as diagnosis and prognosis of the affected teeth is concerned. Hemisection is the treatment choice for perio-endo lesions to preserve the remaining part of the molar having sound periodontium. It is a resection of periodontally involved root along with the associated crown portion. Prognosis and treatment of perio-endo lesions depend on the severity of bone loss, root trunk length, degree of root separation, curvature of root, ability to eradicate the osseous defect, and restorative and oral hygiene procedures. In this case report, root canal treatment and hemisection were successfully performed to treat advanced perio-endo lesions. By this way, natural tooth and surrounding structures were preserved and thereby cost was lesser than the other treatment alternatives.