Several researchers have investigated cellular response, and antibody response to different antigens of group A beta-haemolytic streptococci, cardiac tissues and B cell alloantigen in rheumatic fever (RF). However, immunoglobulins (Ig) which may indicate general immune status did not receive attention. This study was done in the outpatient clinic of the National Center for Control of Rheumatic Fever and Heart Diseases, Dhaka, to compare Ig levels in subjects with and without RF who have had recent group A beta-haemolytic streptococcal infections. We have recruited 44 RF cases aged 5 to 20 years, and 44 subjects without RF were randomly matched for age and sex as controls. Convalescent blood samples were used to measure antistreptolysin O and IgG, IgM, and IgA levels. The cases, as compared with the controls, had significantly higher levels of antistreptolysin O (mean 399 versus 321 IU/ml), IgG (mean 2386 versus 1885 mg/dl), IgM (mean 286 versus 222 mg/dl) and IgA (mean 258 versus 184 mg/dl). It is not clearly known why the immune response is higher in the RF cases. We have to elucidate factors responsible for higher immune response in children with RF.