Peri-implant soft tissues are essential for osseointegration. The peri-implant mucosa may lack vascular supply, and histological observation, even without plaque, shows the presence of inflammatory cells. The objectives of this study were to assess the histopathological changes of the epithelium and connective tissue around the implant. Twenty patients of both genders were studied. Twelve weeks after implant placement, fragments of peri-implant gingival sulcus were harvested and processed for light microscopy. Group I (10): without clinical inflammatory signs (control); Group II (10): with clinical inflammatory signs. Histopathological parameters were analyzed and classified in 3 grades: mild, moderate or severe (grade 1, 2 or 3). Control group showed only slight changes, grade 1. In group II we found edema with moderate to severe cellular and nuclear changes. There are more women than men with all grades of inflammation. All patients with moderate edema are male and all patients with severe edema are female. A significant association (p=0.007) exists between these two variables. Significant differences were found when comparing the degree of inflammation with nuclear alterations (p=0.001) and the same results when comparing the degree of edema and nuclear changes (p<0.001). This study demonstrates that clinical examination can be used, with a small margin of error, to monitor and control the state of the peri-implant mucosa. In clinics the predisposition of female patients to greater degree of edema and inflammation should be accounted for.