The surveillance of Legionnaires' disease (LD) in Europe is carried out by the European Legionnaires' Disease Surveillance Network (ELDSNet) and coordinated by the European Centre for Disease Prevention and Control (ECDC). All cases reported in 2009 and 2010 and meeting the European case definition were electronically transmitted to The European Surveillance System (TESSy) database. A total of 5,551 and 6,305 cases were reported by 29 European countries in 2009 and 2010, respectively. The age-standardised rate of all cases was 1.20 per 100,000 inhabitants in 2010, 12% higher than in 2009, which was consistent with the increasing trend observed since 2005. Most of this increase consisted of community-acquired cases reported by France, Germany and the Netherlands with dates of onset in August–September. The exceptionally hot summer of 2010 in some parts of Europe may have played a role in this increase.