Background: Acute respiratory tract infections are a major cause of under-five childhood morbidity and mortality across the world. Knowledge of pathogenicity and invasiveness of serotypes can help in predicting the course of disease and will permit necessary interventions to be taken in time. This will result in better opportunities of care and significant decrease in morbidity and mortality associated with pneumococcus. The aim of this study to identify the various pneumococcal serotypes affecting children as pneumococcal invasive disease and to study the clinical presentation, invasiveness and the morbidity and mortality caused by them.