German retailers' sales rose by 2.5 percent in August compared with July, the federal statistics office Destatis said in a statement.
It was the steepest increase since June 2011 and better than analysts' expectations.
Retail sales had declined by 1.1 percent the previous month.
On a 12-month basis, business edged by only 0.1 percent in August compared with the same month last year, but that was because there was one less shopping day in August this year than in August 2013, the statisticians calculated.
Retail sales data are subsequent to frequent revision.