Since the launch of the euro in 1999 the inflation differential of Spain relative to the euro area was persistently unfavorable to the Spanish economy, with an average annual rate of one point until 2008. This was a problem, as it entailed a loss of competitiveness. However, since the end of 2008 to the end of 2009 the inflation differential with the euro zone was negative according to the harmonized index of consumer prices (HICP), thus revealing a changing pattern. In 2010 the inflation differential has been positive anew, but more moderately. The aim of this paper is to determine the principal drivers of this differential recently and to forecast the next developments. The fragility of the recent improvement is discussed.