The addition of grafting material to the tunnel procedure has yielded more stable outcomes than the tunnel procedure alone, but currently there is no available evidence about the most effective grafting material. This study compared two grafting materials-subepithelial connective tissue graft (SCTG) and acellular dermal matrix (ADM)-with the modified coronally advanced tunnel technique (MCAT) in the management of multiple adjacent gingival recessions (MAGRs). Patients (n = 24) with recession type 1 MAGR sites were randomly allocated to treatment with ADM+MCAT (test group) or SCTG+MCAT (control group). The clinical parameters were recorded at baseline (before treatment) and 9 months postsurgery and included gingival recession depth (GRD), gingival recession width (GRW), gingival thickness (GT), keratinized tissue width (KTW), probing pocket depth (PPD), clinical attachment level (CAL), and percentage of root coverage. Patient esthetic satisfaction and postoperative pain were recorded using a visual analogue scale (VAS). After 9 months, significant reductions in GRD (2.10 ± 0.64 mm; 2.23 ± 0.68 mm) and GRW (2.41 ± 1.19 mm; 2.41 ± 1.94 mm), increases in GT (0.53 ± 0.41 mm; 0.94 ± 0.52 mm), and gains in CAL (2.46 ± 1.94 mm; 2.47 ± 1.28 mm) were recorded in the test and control groups, respectively. However, the control group showed more KTW gain (P = .0003) and increased GT (P = .002) than the test group. Patient satisfaction with esthetic outcome 9 months after treatment did not differ between test (VAS score: 8.24 ± 0.43) and control (VAS score: 8.24 ± 0.65) groups (P = 0.99). The use of ADM may represent an alternative to SCTG when used in conjunction with MCAT.