Abstract: Bacterial agents of meningitis in children and detection of their antibiotic resistance patterns in Hamadan, Western Iran. Bacterial meningitis is still one of the most dangerous infection diseases and causes serious complications in children. The aim of present study was to identify the most common of bacteria causing meningitis in children under 10 years of age and detection of their resistance to routine antibiotics in Hamadan. Overall 582 children suspected to meningitis were investigated for CSF cultures, elevation of CSF leukocyte count and clinical manifestations, from January 1998 to December 2002 in two hospitals. The required data of patients were gathered through a questionnaire and analyzed using Epi6 system. The species were identified by biochemical and latex-agglutination tests. Antibiogram tests were also performed by gel-diffusion method of Kirby-Bauer. Out of 582 children suspected to meningitis, 146 children (25.1%) had positive bacterial culture that %58.9 of isolates was Gram-positive cocci and %41.1 was also Gram-negative bacteria. The most common isolates were Streptococcus pneumonia (23.9%), Staphylococcus aureus (13.1%), Escherichia coli (10.9%), Neisseria meningitides (6.2%) and Haemophilus influenzae type b (4.1%). The most effective antibiotics against isolates were ceftizoxime, kanamycin and gentamicin while most of isolates showed high resistance to ampicillin, amoxicillin, sulfamthoxazole-trimethoprim and chloramphenicol. The present study showed that Gram-positive bacteria in particular, S. pneumoniae and S. aureus are predominant causes of bacterial meningitis in children involved in this region. Most species showed high resistance to routine antibiotics such as amoxicillin, ampicillin and chloramphenicol. The antimicrobial susceptibility pattern for bacteria causes meningitis may provide a guideline for the selection of appropriate drug treatment.