Introduction: Keratinized gingiva is an important component of the mucogingival complex. Its absence may be due to gingival recessions, trauma, root caries, among others. The free gingival graft technique is considered the gold standard, as it is an optimal technique to increase the extension of the vestibule and the width of the keratinized tissue due to its high success rates and clinical predictability. Objective: The purpose of this clinical case was to evaluate the use of a modification of the free gingival graft technique. Case report: The clinical case included an increase in the depth of the vestibule as well as the keratinized gingiva in both areas of the anteroinferior sector, for which the two hemiarchates of the palate were used as the graft donor area (double graft). The case used a free double gingival graft as a novel technique for gingival augmentation. After two months of healing, a reduction in the gingival recession was observed, as well as a noticeable increase in the width of the keratinized gingiva. Conclusions: The modified free double gingival graft technique is a good alternative to increase the thickness of the keratinized gingiva in the anteroinferior sector, in addition to reducing the post-operative time and generating uniform healing at the level of the mucogingival line.