Measles elimination in Europe is hindered by recurrent outbreaks, typically in non-immunised specific sub-populations. In 2003 and 2004, two measles outbreaks occurred in Jewish ultra-orthodox communities in Jerusalem, Israel. In 2007, another measles outbreak emerged in Jerusalem. Epidemiological investigation and control activities were initiated. Three measles cases (15 years old, 22 years old and an infant; all unvaccinated) were diagnosed in Jerusalem in August 2007. All three belonged to Jewish ultra-orthodox communities in London, United Kingdom, and had had contact with patients in London. The epidemiological investigation did not reveal any connection between these cases other than their place of origin. The disease spread rapidly in extremely ultra-orthodox sub-groups in Jerusalem. Until 8 January 2008, 491 cases were reported. Most patients (70%) were young children (0-14 years old), 96% unimmunized. Frequently, all the children in a large family were infected; two thirds of the cases belonged to family clusters of more than two patients per family (in part due to non-compliance with post-exposure prophylaxis recommendations). The high age-specific incidence among infants 0-1-year- (408.5/100,000) and 1-4-year-olds (264.1/100,000) is a cause for concern. The hospitalisation rate was 15% (71/491), mainly due to fever, patients (26.7%) presented with pneumonitis or pneumonia and two patients presented with encephalitis. There have not been any deaths to date. The outbreak was apparently caused by measles importation into unprotected groups. Despite a high national immunisation coverage (94-95%), programmes to increase and maintain immunisation coverage are essential, with special focus on specific sub-populations.