Background: Juvenile idiopathic arthritis (JIA) is the most common rheumatic disease in children. Both the humoral and cell mediated immunities are involved in the pathogenesis of JIA. It is reported that overall immunoglobulin levels in JIA patients are significantly higher than their control during the active state of disease. Methodology: This prospective observational study was conducted over a period of 18 months All the newly diagnosed oligo-articular and poly-articular JIA patients having active disease were included by purposive sampling. Data were collected by a semi-structured predesigned questionnaire. Result: Most of the study subjects (57.6%) belonged to age group > 3 -9 years. Oligo JIA was diagnosed in 66.7% and poly JIA in 33.3% of JIA children. The difference in mean (±SD) ESR (33.52 ± 21.29 and 15.09 ± 7.71 mm in 1st hour) at active and inactive states was highly significant. Mean (±SD) difference of IgG, IgM and IgA in active and inactive states of disease were highly significant. Conclusion: Higher and abnormal levels of immunoglobulin (IgG, IgM, and IgA) were present among JIA patients in active disease state which became normal during inactive disease state after treatment.