Sepsis is the systemic response to infection manifested as hyperthermia or hypothermia, tachycardia, tachypnea, and shock. This condition represents a major life-threatening factor in all age groups, particularly in neonatal period. The present study aimed to examine the results of blood, cerebrospinal fluid (CSF), and urine culture tests in suspected neonatal sepsis cases in northwestern Iran.This descriptive-analytical study was conducted on suspected neonatal sepsis cases hospitalized in Tabriz Children's Hospital. All subjects underwent complete blood count with white blood differential, C-reactive protein, blood culture and, if deemed necessary, CSF and urine culture tests and analyses. Laboratory findings in positive culture cases were scored based on the hematological scoring system (HSS) for the diagnosis of neonatal sepsis. The data were then collected, entered into SPSS v18 and analyzed.Among 838 suspected neonatal sepsis cases, 102 (12.17%) neonates with positive cultures were examined; 59.8% of whom were male with a mean age of 9.9 days, gestational age of 36.91 weeks, and mean weight of 2.966 kg. 76.47% of neonates with positive culture were term, 69.6% had normal birth weights, 68.6% were diagnoses with late-onset sepsis, 65.68% had positive blood culture, 38.23% had positive urine culture with no positive CSF culture case. Poor feeding (39.21%) and lethargy (35.29%) were the most common clinical symptoms and previous history of hospital stay (40.19%) and surgery (21.56%) the most common risk factors for neonatal sepsis development. Results revealed that 50 (49.01%) neonates achieved HSS scores equal or greater than 2 (HSS ≥2), and that the mean HSS score in deceased positive blood culture neonates was significantly higher than that of survived ones (2.21 vs 1.37). In this study, coagulase-negative staphylococcus and Staphylococcus aureus represented the most common bacteria isolated from blood with 37.31% and 12.43%, respectively. Fungi (38.5%) and Klebsiella (28.20%) were the most common microorganic urine isolates.The results suggested that only a small percentage of suspected neonatal sepsis cases had positive blood and/or urine cultures (12.17%) and that coagulase-negative staphylococcus (CoNS) and S aureus were highly prevalent in positive blood cultures, whereas fungi and Klebsiella were the most common microorganisms found in positive urine cultures.