Clothing and footwear prices fell by 6.4% in May, down from 7.2% and the lowest figure since May 2013.
The 12-month average rate of deflation for clothing and footwear is 9.2%, according to the BRC-Nielsen Shop Price Index published today.
Babywear was the only sub-category not to remain deflationary during the past month, while clothing accessories registered an acceleration in its deflation rate.
The price of cotton fell 28% compared with the same month last year.
Overall shop prices declined 1.9% in May, which is the same rate as April.
Mike Watkins, head of retailer and business insight at Nielsen, said: “Retailers continue to use price cuts and promotions to stimulate sales which is helping to maintain shop price deflation, and we see little evidence to suggest that prices will rise in the near future.
“Deflation and price-led competition will continue to be a key driver of sales growth for some time yet.”