Pericarditis is a rare but recognized complication of meningococcal disease. After the 2000 and 2001 hajj in Saudi Arabia, a worldwide outbreak of meningococcal W135:2a:P1.2,5 (epidemic strain) was reported including the United Kingdom. Cases of meningococcal disease occurred in pilgrims and their household contacts; and community spread occurred among non-Muslims. Between July 2001 and January 2002, 2 children with pericarditis associated with W135 meningococcal disease were admitted to our hospital in east London.