Background:
Sepsis is a systemic inflammatory condition with high mortality rate. It is important to estimate nosocomial sepsis in order to manage the patients earlier. The aim of this study was to investigate the role of hematological parameters in estimating nosocomial sepsis.

Material and Methods:
A retrospective examination was conducted on 121 nosocomial sepsis patients between 01 January 2014 and 30 June 2017. Neutrophil to lymphocyte ratio (NLR) and C-reactive protein (CRP) of the patients at the onset of sepsis were compared with baseline values.

Results:
The mean CRP level of the cohort at admission was 55±5.4 mg/dL and 139.2±6.2 mg/dL at the onset of sepsis (p<0.001). The mean NLR at admission was 10.64±10.6 and 13.69±14.5 at the onset of sepsis (p=0.037). In contrast, the differences in white blood cell, and mean platelet volume values at admission and sepsis onset were not statistically significant (p>0.05). Significant correlation was found between CRP and NLR values at both admission (r=0.365, p<0.001) and at the onset of sepsis (r=0.261, p=0.004).

Conclusion:
We concluded that the NLR is a useful marker in estimating nosocomial sepsis especially when considered together with CRP.