Abstract. Bacillus cereus, a Gram-positive, aerobic spore forming rod, is ubiquitous. Isolation of Bacillus cereus from a normally sterile site (i.e. blood or cerebrospinal fluid) is often disregarded by clinicians as a specimen contamination.We report a case of a 32-week small for gestational age twin preterm infant, of 839 grams birth weight, with non-anthrax bacillus species meningitis. There have been very few reports of meningitis and brain abscesses with these bacteria in low risk preterm infants. Our case was unusual with the development of central diabetes insipidus following bacillus meningoencephalitis and brain abscess. It draws attention to the severe morbidity caused by a relatively benign and usually ignored organism.