The lymphatic system is composed of lymphatic vessels and lymphoid organs such as the thymus, tonsils, lymph nodes, and spleen. Lymph nodes are small glands that are responsible for filtering fluid from the lymphatic system. Lymphadenopathy refers to the enlargement of lymph nodes that can occur due to autoimmune disease, malignancy or microbial infections. Immunological investigations were done from 2018 to 2023 to children with lymphadenopathy to help in diagnosis the causes of lymphadenopathy. Viruses as Epstein-Barr virus and cytomegalovirus were detected in blood samples by immunoassays. The obtained results indicated presence of Epstein-Barr virus and (45.5%), cytomegalovirus (18.2%) in children with lymphadenopathy. The results showed no significant differences in levels of serum Anti-Nuclear Antibody (ANA) for children with lymphadenopathy compared with their levels in healthy control children. Only one case (2.9%) out of 35 children with lymphadenopathy was diagnosed with Kawasaki disease and had positive ANA test. There was no significant difference in immunoglobulin A (IgA) in children with lymphadenopathy compared to their levels in healthy control children.