The purpose of the present case report is to clinically and histologically evaluate the healing of one advanced intrabony defect following treatment with an enamel matrix protein derivative (EMD) combined with a bovine-derived xenograft (BDX) and guided tissue regeneration (GTR). One patient with generalized chronic periodontitis and one advanced intrabony defect was treated with EMD + BDX + GTR. Notches were placed in the root at the level of the calculus and alveolar crest to aid histologic identification of new periodontal tissues. Postoperative healing was uneventful. At the 7-month histologic examination, healing in the intrabony component of the defect was characterized by formation of new connective tissue attachment (new cellular cementum with inserting collagen fibers) and new bone in the intrabony component. The BDX particles were surrounded by bone-like tissue. No direct contact between the graft particles and root surface (cementum or dentin) was observed. Healing in the suprabony defect component occurred through epithelial downgrowth that stopped at the level of the coronal notch. The BDX particles were entirely encapsulated in dense connective tissue, without any signs of bone formation. The present case report shows formation of new attachment apparatus consisting of new bone, cementum, and periodontal ligament in the intrabony component of one human defect treated with EMD + BDX + GTR.