Background. Recently, the use of leukocyte- and platelet-rich fibrin (L-PRF) has been recommended due to the presence of various growth factors to increase the success of free gingival grafts (FGG). This study evaluated the effect of using L-PRF in the healing of FGG in rabbits. Methods. Twenty rabbits were randomly divided into two groups. In each group, FGG was performed in two separate sites with or without L-PRF. One of these groups was sacrificed on the 7th day and the other on the 28th day and analyzed in terms of clinical indices, including wound healing, gingi­val thickness (GT), and keratinized tissue width (KTW). Then histologic sections were obtained and stained for type and degree of inflammation and rate of vascular formation analysis. SPSS 22 was used for statistical analysis. Results. The extent of changes in GT, KTW, wound healing index, and vascular formation between the test and control groups was not statistically significant. The difference in the type of inflammation was significant only between the -7day and -28day control groups (P=0.003). The degree of inflammation between the -7day test group and the -28day control group, as well as the -7day and -28day control groups, were statistically significant (P=0.011 and P=0.002, respectively). Conclusion. Using L-PRF with FGG could improve FGG healing compared to using FGG alone, but the results were not statistically significant.