Aims: This parallel-group, multi-centre, double-blind, randomized-controlled clinical trial was undertaken to compare the clinical outcomes of coronally advanced flap (CAF) alone or in combination with a connective tissue graft (CAF+CTG) in single Miller Class I and II gingival recessions. Material and Methods: 80 patients were enrolled with one recession each. Coronally advanced flap (CAF) alone surgery was performed in 30 patients; 30 sites randomly received a graft under the CAF. Measurements were taken by blind and calibrated examiners. Outcome measures included recession reduction, complete root coverage (CRC) and side effects. Results: No differences were noted in the intra-operative and post-operative patient related variables between the two groups. Surgical time was significantly shorter in the CAF group. Recession reduction was not statistically different between the two groups; even though test group showed a tendency towards improved outcomes in sites treated with CAF+CTG (adjusted difference 0.33mm. statistically Significant results of PD, KT and CAL were observed after CAF+CTG (≤ p = 0.0033). Conclusion: Both treatments were effective in providing a significant reduction of the baseline recession and with only limited intra-operative and post-operative morbidity and side effects. Adjunctive application of a CTG under a CAF increased the probability of achieving decrease PD, increase KT and CAL Miller Class I and II defects. Conflict of interest: No conflict of interest declared by any of the Authors.