P>Fungal infections are increasingly frequent causes of neonatal sepsis (NS). This study examined the predictive value of the combined evaluation of the C-reactive protein (CRP) and interleukin-6 (IL-6) responses for differentiating fungal and bacterial aetiologies in patients with NS. From January to September 2007, neonates who were diagnosed with NS and had their CRP and IL-6 levels measured were selected. Based on their blood culture results, the neonates were divided into two groups: group of fungal sepsis (FS) and group of bacterial sepsis (BS). FS included 14 Candida albicans and one non-albicans Candida isolates and BS included five Klebsiella pneumoniae, three Pseudomonas aeruginosa, three Enterococcus faecalis, two coagulase-negative Staphylococcus species, one Enterococcus faecium and one Acinetobacter species. Significant differences were observed in the CRP (FS vs. BS: 28.10 +/- 11.03 vs. 11.39 +/- 2.94 mg l-1, P = 0.026) and IL-6 (FS vs. BS: 38.60 +/- 24.24 vs. 392.82 +/- 102.46 ng l-1, P = 0.000) levels between groups. The combined evaluation of the CRP and IL-6 responses better predicted the causative micro-organism in NS.