Grafting connective tissue from the palate to partial-thickness sites prepared in patients with an inadequate width of attached gingiva resulted in an increased width of keratinized mucosa. Biopsies of these grafts at the newly created mucogingival junction at 24 weeks showed the epithelium to be keratinized with a normal architecture, except over scar tissue at the edges of the grafts, where rete-peg formation was absent. The results support the concept that morphodifferentiation of gingival epithelium is influenced by the underlying connective tissue.