Streptococcus pyogenes (Group A Streptococcus/GAS) is the most prevalent human bacterial pathogens amongst streptocoocus species. It causes a wide range of suppurative infections in the respiratory tract and skin, life-threatening soft tissue infections, and certain types of toxin associated reactions. Some of these infections may, in addition, result in severe non-suppurative sequelae due to adverse immunological reactions induced by the infecting streptococci. As the diagnosis of

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... ve infection caused Streptococcus pyogenes is only depends on immunological reaction, present study was carried out to see the sero-prevalence of Anti-streptolysin O antibodies in our region. Material & Methods: In the present prospective study was carried out in the Department of Microbiology under serology section at a tertiary care hospital from January 2015 to December 2016. Blood samples were taken from clinical suspicion cases of streptococcal infection. All samples were tested by using qualitative and semi-quantitative antibody detection method as per the standard guidelines. Results: A total of 1526 blood samples were collected and processed for the detection anti-streptolysin O antibodies. Out of which 92 (6.03%) were positive for ASO, among them 59 were from out door-patients department and 33 were from indoor-patients department. Out of 92 positive cases, 48 were males and 44 were female patients. Highest positive cases were found in the age group of 11-20 years (7.15), followed by the age group of 21-30 years where the prevalence was found to be 6.40%. Conclusion: The presence of elevated streptococcal antibody titers in such population, which probably reflects a high background prevalence of streptococcal infections, should be taken into consideration when evaluating the role of the group A streptococcus in non-purulent complications of infections.