The development of the thyroglobulin immunoradiometric assay (Tg-IRMA) using solid phase coated plates is the primary goal of this work. Three components were prepared and characterized for the Tg-IRMA method. The first component was polyclonal antibody of thyroglobulin (anti-Tg), that was generate via immunized three Balb/C mice against highly purified Tg antigen. The vaccination schedule was followed, consisting of the initial vaccination and three booster injections. The second component was radioiodinated both of Tg antigen and Tg monoclonal antibody (Tg-MoAb) with radioactive iodin-125 (Na 125I) to prepare two radioactive tracers, first one was 125I-Tg* radioactive tracer used for characterized the produced anti-Tg polyclonal and second one was 125I–Tg-MoAb* radioactive tracer to use in established solid phase coated-plate Tg-IRMA technique. Additionally, set of Tg standards with different concentration was prepared and evaluated with commercial Tg-IRMA Dia-Source kits. The optimization and validation tests were studies to obtained accurate, precis and valid local prepared system. Finally, locally produced solid phase coated-plate Tg-IRMA may be very useful in the in-vitro evaluation of thyroglobulin in human serum to diagnose and treat disorders of hyperthyroidism and hypothyroidism, as well as in following the progress of treatment for thyroid cancer and recognize recurrence. In general, preparing the immunoradiometric system is considered one of the most important diagnostic radiological applications in the practical medical field