The shrinkage of free gingival grafts ( FGGs) is a well-known clinical phenomenon but there are limited studies demonstrating the dimensional changes during healing in FGGs. The aim of the study is to examine the shrinkage of FGG in both horizontal and vertical dimensions and calculate the changes in the surface area of the graft at early and delayed periods of healing. The FGG procedure was applied to 15 consecutive patients in their mandibular anterior area. The graft sizes and areas were measured and the shrinkage of the graft was calculated at baseline and days 10, 21 and 180. Hemorrhage, sense alteration and pain symptoms were also examined. Change in the horizontal direction was not statistically significant during the whole study period ( p> 0.05). However, there was a statistically significant reduction in the vertical direction in all visits, except day 10 ( p< 0.05). Calculated graft area was also significantly reduced during the study period at all time-points compared to the baseline ( p< 0.001). At day 10, 4 (26.7%) recipient sites and 5 (33%) donor sites demonstrated paresthesia. Only one ( 0.07%) recipient site demonstrated paresthesia at day 21 where the donor site resulted with an uneventful healing. At day 10, 5 ( 33%) patients demonstrated bleeding at their donor regions and resulted with a complete cessation of bleeding at day 21. Pain symptom was found in 8 (53.3%) recipient sites where 3 (20%) donor regions presented pain symptom at day 10. Graft shrinkage in the vertical dimension seems to affect the clinical outcomes of the FGG procedure. However, the influence of horizontal graft shrinkage was minimal.