The aim of this study was to evaluate histomorphometrically the effects of Emdogain, a commercial preparation of enamel matrix derivative (EMD), on the gingival soft tissue thickness in dehiscence-type osseous defects in a dog model. Buccal osseous dehiscences were surgically created on the maxillary canines and the second and fourth premolars of five adult female beagle dogs. Thirty defect sites were randomly assigned to test and control groups (15 sites/group). The test group received an EMD application whereas the control group received none. After 4 months of healing, the dogs were sacrificed and tissue blocks were prepared. The mean gingival tissue thickness was found to be 1.76 ± 0.23 mm at the EMD-treated sites compared with 0.72 ± 0.11 mm at the control sites, showing a statistically significant difference (P < 0.0001) between the groups. Within the limits of this study, it can be concluded that EMD significantly increases the gingival tissue thickness when used in dehiscence-type defects in beagle dogs.