Leukocyte- and platelet-rich fibrin (L-PRF) belongs to a new generation of platelet concentrates. There are limited numbers of studies focused on the use of L-PRF in gingival recession defects. This study evaluated the safety and effectiveness of using L-PRF membranes as a substitute for free connective tissue grafts (CTGs) as a treatment method for gingival recession defects. A total of 44 Miller Class I/II gingival recessions that were bilateral, adjacent, and greater than 3 mm in size were selected. Each recession site was randomly assigned to the test group (L-PRF) or the control group (CTG). After 12 months, root coverage was 76.63% and 77.36% in the L-PRF and CTG groups, respectively. It is suggested that L-PRF membrane may be an alternative graft material for treating multiple adjacent recessions greater than 3 mm in size without a requirement for additional surgery.