•We use DEA to assess efficiency of European air navigation service providers.•Technical efficiency does not vary much across providers, unlike allocative efficiency.•Since 2008, some prior efficiency gains have been erased. This study uses EUROCONTROL data on operating performance of the national air navigation service providers over the 2002–2011 time period to document in detail the efficiency changes across providers and time using data envelopment analysis. Our results suggest that overall providers’ productivity improved over the time period covered by the data, driven by improvements in technical rather than allocative efficiency. However, some trend reversals in the post-2008 crisis period are also observed.