A two episodes case of CSF ventriculo-atrial shunt infection due to B. circulans and B. larvae is presented. B. circulans was first isolated from 4 blood cultures and CSF (shunt valve tap). The patient showed a brain damage syndrome reversible with antibiotic treatment. Lethal toxin production was demonstrated for the B. circulans strain in a mouse model. This strain was found to be a variant of Gordon's description as it produced urease and was tolerant to 7% NaCl. The patient recovered after cefotaxime, cotrimoxazole and rifampicin treatment. A second infection due to B. larvae was detected two months later. The shunt system was removed due to obstruction and a scanning electron microscopy study was performed. Confluent masses of white blood cells and rods were observed on the inner surface of the catheter. As for as we know, this is the first case of human infection due to B. larvae.