The purpose of this in vitro study was to determine the ability of seeded and not-seeded commercial pediatric blood culture bottles to support the growth of the most frequently responsible microorganisms for bacterial meningitides (Neisseria meningitidis, and Haemophilus influenzae). Tests have been carried out with an automated colorimetric pediatric blood culture system, BacTAlert, Organon Teknika. Bottles were inoculated with X–V factors and serial dilutions of the each bacterium in six times (10 1 –10 6 colony forming unit [CFU]/ml). The bottles, which were supplemented with X–V factors, proved to be effective and time to detection (TTD) was shorter than the un-seeded bottles (p⩽0.05). Time difference between seeded and not-seeded bottles was getting greater at high dilutions of both bacteria. We consider that in presence of a few bacteria, the seeding of bottles with X–V factors is very critical obtaining N. meningitidis, and H. influenzae as the causative agents of meningitidis. The recovery rate of the microorganisms, which were isolated from cerebrospinal fluid by using the X–V factor-seeded blood culture bottles, is therefore higher than with the conventional culture methods.