From August 2012, retail sales dropped 0.3 percent in the 17-member currency union. Sales, however, rose 0.3 percent in the European Union from August 2012.
The EU is a 28-member region that included 27 members in June, as Croatia joined on July 1.
Data was also unavailable or held back from the Czech Republic, Greece, Croatia, Italy, Cyprus, Hungary and the Netherlands.
Among reporting countries, the largest increases month to month were posted by Portugal with a gain of 4.8 percent. Luxembourg, with a decline of 1.4 percent, posted the largest month to month drop.