Background: Periodontitis is an inflammatory disease of the supporting tissues of the tooth caused by specific microorganisms in a susceptible host. Subgingival microflora plaque formation as a series of successive waves of colonization by increasingly periodontopathogenic clusters of bacteria. The microflora shifts from gram positive to gram negative microbes and rods. The most pathogenic microbial cluster is the red complex which consists of the P. gingivalis, T. Forsythia and T denticola species. The primary goal of periodontal therapy is to preserve the natural dentition by achieving and maintaining a healthy functional periodontium. It consists of patient motivation and oral hygiene instructions as well as mechanical removal of supra and subgingival plaque and calculus deposits, correction of plaque-retentive factors and risk factor modification. Aim of the study: To study effects of nonsurgical periodontal therapy on blood parameters and periodontal status. Materials and methods: This study was carried out in the department of periodontology, AMC Dental college and hospital, Ahmedabad. A randomized control trial was conducted on 75 patients which were systemically healthy and aged between 30-55 years. Periodontal parameters included in the study were recorded with following indices: Plaque Index (PI), Gingival Index (GI), Probing Pocket Depth (PPD), and Clinical Attachment Level (CAL). Blood investigations include measurement of: Hemoglobin (Hb), Red Blood Cell (RBC) Count, White Blood Cell (WBC) Count, Erythrocyte Sedimentation Rate (ESR), Mean Corpuscular Volume (MCV), Mean Corpuscular Haemoglobin (MCH), Mean Corpuscular Haemoglobin Concentration (MCHC), Pack Cell Volume (PCV). Results: The analysis of demographic variables shows that 37 (49.3 %) were females and 38 (50.7%) were males. All hematological parameters showed improvement from baseline to 3 months in all three groups in the present study. A statistically significant increase in Hb levels from 12.32 to 12.67 gm/dl in healthy control group, from 12.70 to 13.02 gm/dl in generalized chronic gingivitis group and from 11.48 to 11.93 gm /dl in generalized chronic periodontitis from base line to 3 months. Thus a mean increase of 0.35 gm/dl in healthy control group ,0.32 gm/dl in generalized chronic gingivitis group, 0.45 gm/dl in generalized chronic periodontitis from baseline to 3 months. Thus, slight more improvement was seen in generalized chronic periodontitis. Conclusion: Future long – term studies with a large sample size should be carried out to further explore of the study. The results have been shown that increase in blood parameters after nonsurgical periodontal therapy , will improve physical status of patients in some degree.