Total sales fell 0.9% compared to 0.7% in August 2011, while like-for-like sales dropped by 2.7% against 2.1% previous year.
The Olympic month witnessed a real term decline of 2% in total sales, after accounting for inflation, reported British Retail Consortium (BRC).
Except for total food sales, which saw 2.4% jump in August 2012 over 1.4% last year in view of party foods during Olympics and warmer time, the remaining streams have experienced decline.
Total non-food sales dropped by 4.1% on a year earlier, when they had declined by 2.6%. The 6.7% decline over 24 months is the worst since the survey started in 1999.
Total retail sales growth is still 2.5% points below the whole of the UK with no sign that the gap will be closing any time soon.
SRC economist Richard Lim said that the games have not given the required push to Scottish retail sales.
"Some sectors suffered less than others. Food sales growth was noticeably better in August than in July. The Games helped sales of party food and drink but the hot spell in the middle of the month dampened demand for autumn and winter clothing ranges arriving in stores," Lim added.
KPMG Scotland head of Retail David McCorquodale said that the impact on retailer’s profitability will be ascertained over next three months since August is traditionally a weak month for high street spending.
"Without doubt, the Olympics and Paralympics brought a much needed feel good factor to consumers but the country was ‘otherwise engaged’ in August and the retail sales figures show a mixed picture," McCorquodale added.