Preliminary data show German retail sales fell 0.3 percent on the month in July - although they were 0.8 percent higher in annual terms.
The monthly dip reported by the Federal Statistical Office Wednesday compared with economists' expectations of a 0.5 percent increase.
The agency didn't disclose what caused the rise, though UniCredit economist Alexander Koch pointed to falling sales of televisions following a World Cup boom as a likely reason.
Sales for the January-July period were up 0.9 percent over a year earlier.
German retail sales figures are frequently revised. Citing methodical changes, the statistical office recently reported first-half sales were up 0.9 percent year-on-year - compared with a 0.4 percent drop initially reported. - Sapa-AP