Objective To evaluate the clinical efficacy of xenogeneic acellular dermal matrix (XADM) or connective tissue graft (CTG) combined with modified-coronally advanced flap (M-CAF) in the treatment of multiple gingival recessions. Materials and methods Twelve participants with bilateral MGRs (multiple gingival recession) (82 gingival recessions) randomly received XADM (test group, 41 teeth) on one side and subepithelial CTG (control group, 41 teeth) on the other side in conjunction with M-CAF in the same session and completed the 18-months study period. Recession depth (RD), recession width (RW), keratinized tissue width (KTW), probing depth (PD), and clinical attachment level (CAL) were recorded at baseline, and 6-, 18-months postoperatively. Results PD was significantly higher in the test group at 18-months (P < .05). PD in the test group was also significantly higher at 6- and 18-months compared to baseline (P < .05). RD and RW were significantly lower at 6- and 18-months compared to baseline in both groups (P < .05) and both parameters were significantly higher in the test group at 18-months (P < .05). Percentage of teeth with complete root coverage in the test and control groups were similar at 6-months (78% and 70.7%, respectively) and at 18-months (both 87.8%) (P > .05). Conclusion Within the limits of the study, M-CAF combined with XADM or CTG seems to be similarly effective in RD reduction of class I and II MGRs at least in the short term. Soft tissue shrinkage and increase in PD may be observed with XADM, while; CTG seems to provide stable clinical outcomes for 18-months follow-up. Clinical significance Even though the CTG and XADM in conjunction with M-CAF may provide similar RD reduction in class I and II multiple gingival recessions in the short term. CTGs may be superior in terms of soft tissue shrinkage and PD values.