Neisseria meningitidis is an encapsulated Gram-negative diplococcus which colonises the upper respiratory tract without causing symptoms in up to 25% of the population. At least 13 different serogroups cause invasive meningococcal disease (IND). In the UK serogroup B causes more than 80% of cases of invasive disease. More than 75% of cases occur in the under 5s, reflecting the lack of ability of the immature immune system to mount an effective response to the polysaccharide capsule of the organism. There is also a peak around adolescence. Meningococcal disease can present with features of septicaemia, fever, purpura, and rapidly progressive shock, or with meningitis which can occur without a rash. Many cases have a mixed picture. Young infants with meningitis may not display the classical signs, but appear unwell, lethargic and floppy Petechiae which start to spread, become purpuric, occur in association with signs of shock or meningitis, or in any child who appears ill should always be treated as IMD until proven otherwise. Any child with symptoms and signs suggestive of IMD and a non-blanching rash should be transferred to hospital as an emergency immediately. IM (or IV) benzylpenicillin (or ceftriaxone) should be given at the earliest opportunity, but treatment should not delay transfer. if the child does not have features suggestive of IMD at the time of initial assessment it is important to give parents advice regarding symptoms and signs which may suggest deterioration.