This study evaluates the success of immediate endosseous implants placed along with autogenous bone graft to fill the peri-implant gap. Thirty-two implants were inserted in 8 beagle dogs. The right and left lateral incisors in the maxilla and the mandible of all animals were extracted, and immediate postextraction implants were placed. In the control sites, no bone grafts or barrier membranes were used. In the contralateral experimental site, autogenous bone graft was used. The implants were retrieved with the jawbone for histomorphometric studies. The histomorphometric measurements were carried out using a computerized image analysis system. All implants were covered by compact, mature bone under examination in light microscopy. A high bone-implant contact percentage and bone density was observed at both grafted and nongrafted implant sites. The sites filled with autogenous bone graft showed a significantly higher crestal bone level and bone density compared to the nonfilled sites. The observations of the study emphasize that the filling of the peri-implant bone defects with autogenous bone grafts showed a better outcome compared to unfilled defects.