This study demonstrates a method of earlier identification of BSI pathogens based on the understanding of minimal microorganism concentrations required for positive blood culture in BACTEC FX and for positive identification by MALDI-TOF MS. The time saved by earlier identification of five common BSI pathogens (E. coli, K. pneumoniae, P. aeruginosa, S. haemolyticus, and S. aureus) was 1.7–2.3 hours.