Twenty‐four(24)deep wide buccal gingivalrecessions were treated with ePTFE membrane according to guided tissue regeneration principles (GTR). Factors affecting the surgical outcome of the regenerative procedure were retrospectively analyzed. In 16 cases, the barrier membrane was used in conjunction with tetracycline root conditioning and fibrin‐fibronectin system application, and 8 cases were treated with the membrane alone. Healing response was evaluated 12 months after surgery. Since no difference was observed between the two treatment protocols, all available data were grouped. Mean recession depth was reduced from 4.6 mm to 1.3 mm postoperatively, which represents an average root coverage of 71.7%. Fifty percent (50%) of the cases showed clinical attachment gain greater than or equal to 4 mm and a mean increase of keratinized tissue of 1.0 mm was observed. Baseline recession depth and extent of membrane exposure at the reentry procedure significantly influenced the amount of newly‐formed tissue under the membrane. Recession reduction positively correlated with the preoperative recession depth and the regenerated tissue gain. Treatment was also affected by tooth location, recession reduction, and attachment gain, being significantly greater in upper than lower archs. Results suggest that GTR technique represents a predictable procedure to improve the soft tissue conditions of deep mucogingival defects. Randomized controlled trials of other forms of management of mucogingival defects as compared to the GTR technique will be necessary to fully evaluate the utility of the GTR technique.J Periodontol 1995; 66:14–22.