This study sought to evaluate the efficacy of the Bactec blood culture system for culturing sterile body fluids, in comparison with traditional culture methods. A total of 906 specimens were cultured using both conventional media and the Bactec detection system. Differences in numbers of isolates determined by each system were compared. Clinically significant microorganisms were isolated from 15.3% (139) of 906 specimens by both the Bactec system and conventional culture, whereas for 8.8% (80) of the specimens a positive culture was obtained by Bactec only. Of the 80 specimens in which growth was detected only in the Bactec blood culture system, 11.0% were comprised of cerebrospinal fluid, 9.9% peritoneal fluid, 4.9% pleural fluid, 4.5% synovial fluid and 9.1% bone marrow materials. Strains of Brucella melitensis, Neisseria meningitidis, Pseudomonas fluorescens and Rothia dentocariosa were cultured only by the Bactec system. In conclusion, the Bactec blood culture system might be advantageous for isolation of fastidious microorganisms such as Brucella, especially from cerebrospinal and peritoneal fluid specimens. (c) 2005 Elsevier SAS. All rights reserved.