Background: Anemia of chronic disease (ACD) occurs in the presence of chronic infection, inflammatory conditions or neoplastic conditions despite of adequate iron and vitamins storage. Gingivitis is the inflammation of the gingiva, periodontitis is the inflammation in the periodontium that extend deeper with loss of connective tissue attachment and supporting bone. The main pathogenesis of periodontal diseases and ACD is immune activation. Aims of study: Determine and compare the clinical periodontal parameters (plaque index (PLI), gingival index (GI), bleeding on probing (BOP), probing pocket depth (PPD) and clinical attachment level (CAL)). Evaluate the hematocrit (Hct) level, red blood cells (RBCs) count and white blood cells (WBCs) count. Assess the correlations between the clinical periodontal parameters and hematological parameters at patients had gingivitis, chronic periodontitis (CP) with different severities (mild, moderate and severe) with healthy periodontium subjects. Materials and Methods: 35-50 years old, 150 male subjects were included in this study. They were divided into three study groups: group of 30 patients with gingivitis, group of 90 patients with CP which subdivided into (Mild CP=30 patients, Moderate CP =30 patients, Severe CP =30 patients) and control group 30 subjects with clinically healthy periodontium. Blood samples were collected then by automated blood analyzer the Hct, RBCs and WBCs were evaluated. Results: Comparisons among groups and subgroups revealed significant differences in Hct and WBCs, while RBCs was non-significant. Means values of RBCs count showed reduction in mild and severe CP subgroups. while, the Hct and WBCs mean values increased in patients with periodontal disease. The correlations between the clinical periodontal parameters with WBCs and RBCs were almost non-significant but, with Hct was mostly significant negative correlations. Conclusion: Inflammatory and immune responses in periodontal diseases caused change in different hematologic parameters which could contribute to the development of anemia of chronic disease.