Bacteraemia and septicaemia are generally thought to be relative or absolute contraindications for central neural axis (CNA) blocks. Postulated mechanisms for haematogenous infection of the central nervous system (CNS) caused by subarachnoid or epidural puncture might be an accidental vessel puncture, a change of pressure in the subarachnoid space, and the induction of a "locus minoris resistentiae." Infectious complications of diagnostic lumbar puncture, spinal or epidural anaesthesia are very rare. Although in animals meningitis can be induced by subarachnoid puncture during bactaeremia, there is no study that proves an increased risk for bacteraemic patients. Transient bacteraemia is common, especially in urological and obstetrical-gynecological procedures that are often done in regional anaesthesia, but the incidence of infectious complications is low. This review investigates the few published cases in which a haematogenous infection of the CNS may have been caused by regional anaesthesia. Based on current knowledge, bacteraemia cannot be an absolute, but only a relative contraindication for CNA blocks. Antibiotic chemoprophylaxis should be given before the puncture and the patients must be closely followed after the anaesthesia, particularly for the development of spinal epidural abscess. Because of the possibly increased risk of infectious complications, informed consent should be obtained from the patient.