Thalassemias are inherited haemoglobin disorders characterized by reduced synthesis of one or more globin chains of adult hemoglobin, HbA (α2β2). The α and β thalassemia’s are the most common classes, β-thalassemia is caused by deficient synthesis of β chains, whereas α-thalassemia is caused by deficient synthesis of α chains.This imbalance in globin chain synthesis causes varying degree of anemia, due to ineffective erythropoiesis and hemolysis. Red blood cell degradation and transfusion in thalassemic patients leads to excess iron deposits in vital organs like heart, liver, spleen, pancreas and endocrine organs. Iron overload, poor compliance to therapy and chronicity of the disease have contributed to a spectrum of complications like growth retardation, cardiac problems, liver failure, hypogonadism, diabetes mellitus, hypothyroidism, hypoparathyroidism and metabolic problems in adolescents. The aim of the present study is to evaluate and compare the haematological and biochemical parameters in β Thalassemia patients. Total 49 known cases of beta thalassemia were selected for the study. Detail clinical history and blood samples were collected from all the patients. The samples were subjected for haematological, biochemical and serological analysis. Complete blood picture was performed on Sysmex XN 350. Biochemical parameters like liver function tests and renal function tests were performed on ERBA EM 200. Thyroid function tests, serum ferritin estimation and viral screening (CMIA Method) were performed by Abbott Architect. The results were tabulated and compared to derive the correlation between the different parameter in thalassemic patients. The haematological and biochemical parameters of thalassemic patients showed much variation from the reference ranges in our study.