Background Bloodstream infections (BSls) remain a major cause of morbidity and mortality in patients undergoing surgery.This study aimed at elucidating the clinical characteristics of community-acquired BSls (CABs) and nosocomial BSls (nBSls) in patients admitted to the surgical wards of a teaching hospital in Beijing,China.Methods This cross-sectional study compared 191 episodes of BSls in 4074 patients admitted to the surgical wards between January 2008 and December 2011.Cases of BSls were classified as CABs or nBSls,and the characteristics,relevant treatments,and outcomes of CABs and nBSls were compared.Results Of the 191 BSls,52 (27.2％) and 139 (72.8％) were CABs and nBSls,respectively.Eschedchia coli,coagulasenegative staphylococci,and Klebsiella spp,were the most frequently isolated microorganisms.There were significant differences between CABs and nBSls with respect to the use of hormonal drugs,ventilation,acute physiology and chronic health evaluation (APACHE) Ⅱ and American Society of Anesthesiologists scores,and prevalence of cancer (P ＜0.05).Empirical antibacterial therapy did not decrease the crude mortality,but multivariate analysis showed that high APACHE Ⅱ was independently associated with a risk of mortality (odds ratio =0.97,95％ confidence interval:0.93-1.02 for APACHE Ⅱ).Conclusions We found significant differences in the clinical characteristics of surgical patients with CABs and nBSls.The outcome of patients seems to be related to high APACHE Ⅱ scores.