Smoking has a negative effect on the predictability and stability of root coverage procedures because of decreased blood supply and fibroblast activity. Long-term evaluation of this procedure in smokers is important for clinical decision making, because it provides information about the stability of results over time. In smokers, enamel matrix derivative (EMD) used at acellular dermal matrix graft (ADMG)/ soft tissue interface could be an alternative to improve the deficient healing potential, since EMD has the capability of stimulating angiogenesis. At the ADMG/ root surface interface, it could improve the deficient fibroblast activity in smokers and therefore reduce the presence of a long junctional epithelium. The aim of this randomised controlled clinical study was to investigate whether EMD contributes to the root coverage of gingival recessions performed with ADMG in smokers during a 12-month follow-up.