---

Abstract Background and objectives: The aim of this study was the detection of S.pneumoniae infection by rapid urinary test and blood culture in children with pneumonia in comparison with healthy children. Material and Methods: This case control study was carried out in pediatric ward of Rasoul Akram hospital in Tehran, Iran (2006 - 200٧).Fifty-four Community acquired pneumonia (CAP) and 50 healthy children were selected by simple sampling. The urinary antigen detection test (BINAX NOW co.) was performed on both cases and controls and blood culture was done for the cases suffered from Pneumonia. Results: Pneumococcal antigenuria is detected in 31.5 % of CAP and 6 % of controls groups. There is Significant difference between cases and controls (fisher test CI 95%, P =0.01). None of the children with nonpneumococcal Pneumonia (positive culture) has antigenuria. Conclusion: The possibility of diagnosis of pneumococcal pneumonia in children, by means of blood culture, is low. Thirty-one percent of CAP is due to S.pneumonia, by using the rapid antigenuria test. There fore, we recommend using rapid urinary antigen test, in addition to blood Culture test. Key words: CAP (community-acquired pneumonia) S pneumoniae urinary antigen test (BINAX now), Blood culture, Children