objectives The aim was to analyze injury trends according to age, severity, work activiry and business cycle in the constnaction sector Method From 19so to 2010 a total of 23 464 work related injuries were treated at the emergency department at Odense University Hospital The annual incidences were calculated Employment levels in the construction sector were used as an indicator of fluctuations in the business cycle since 1980. Resulbc Through the last three decades the overall trend of work-elated injuries was unchanged Ror some subgroups of injuries, such as major injuries and injuries due to young workers use of small powered tools significant downward trends were seen but trends within different age groups of workers were unchanged and young workers have at least twice the risk compared to older workers, The tuctuations in work injury trends among workers under 30 years of age were significantly related to the business cycle, where the risk of injuries was higher during economic booms than during recessions. Further periods with economic booms are positively related to the rate of minor injuries and injuries due to all other work activities than the use of power tools. Carschesian overall the number of in the construction sector have not changed significantly dur- injuries ing the recent three decades, except for minor subgroups related to major injuries and injuries due to use of small power tools Re-evaluation of safety prevention programs is needed in order to break the th injury level among young workers compared to older workers, especially during economic booms. o 2016 Published by Elsevier Ltd