Better cancer treatment has led to a steadily growing population of cancer survivors suffering from late adverse effects after cancer treatment. The aim of this study was to investigate whether there has been an increase in free flap reconstruction due to osteoradionecrosis (ORN). A retrospective review was conducted to identify all consecutive head and neck free flap reconstructions performed over an 18-year period (1995–2012) at Karolinska University Hospital. A total of 235 free flaps were identified. Cases were divided into two groups: head and neck cancer reconstructions and ORN reconstructions. A comparison between the two groups showed longer survival (P<0.001) and higher rates of late complications (P<0.001) among ORN cases. ORN as an indication for reconstruction increased over time, from 7.0% of the total number of free flaps performed in 1995–2000, to 15.2% during the period 2001–2006, and to 27.3% in 2007–2012 (P<0.001). This, in accordance with the results of other studies, highlights the importance of the appropriate allocation of resources within the healthcare system to treat this patient group within the steadily increasing population of cancer survivors.