The goal of this study was to evaluate the influence of gingival phenotype (GPh) on the clinical outcomes of coronally advanced flap (CAF). In this prospective study, 24 gingival recessions (recession type RT1 class or Miller Classes I and II) in 21 patients were treated with CAF alone. Patients were classified as having thin, medium, thick, or very thick GPh using a color-coded probe. At 6 months, the lowest mean root coverage (mRC; 60.4% ± 28.8%) and complete root coverage (CRC; 25%) were found in patients with thin GPh compared to patients with medium (mRC: 86.4% ± 17.6%; CRC: 60%), thick (mRC: 93.3% ± 14.9%; CRC: 83.3%), and very thick (mRC: 86.7% ± 26.7%; CRC: 80%) GPh. Regression analysis showed a statistically significant difference (P < .05) between thin and thick/very thick GPh in the likelihood of achieving CRC. Higher RES values were observed in patients with thick and very thick GPh (8.2 ± 1.5 and 8.4 ± 1.4, respectively), while thin GPh was related to the lowest RES score (6.3 ± 2.2). CAF performed in patients with thick or very thick GPh resulted in superior clinical and esthetic outcomes than thin and medium GPh. In particular, thin GPh was associated with the lowest mRC, CRC, and root coverage esthetic scores.