Woolworths has reported a 4.6% drop in like-for-like sales over the key Christmas trading period.
Woolworths struggled to perform over Christmas
The troubled High Street retailer said it experienced weakness in CD, DVD and seasonal confectionery sales during the six weeks to 13 January.
Woolworths warned in December that its full-year profits would plunge if its like-for-like sales, which ignore the effect of new stores, did not improve.
The firm is facing tough competition in its market from the likes of Tesco.
The latest fall in sales at Woolworths follows a previously reported drop of 6.5% for the 18 weeks to the beginning of December.
Woolworths said its most difficult sales areas over the festive period had been "CD, DVD and seasonal confectionery product categories where market weakness was driven by marked price deflation".
"Woolworths retail found some of its traditional markets more difficult, leading to disappointing like-for-like sales over the Christmas weeks," said chief executive Trevor Bish-Jones.
"Despite this, stock levels have been well controlled and we continue to improve gross margins."
Separately, the firm said it was buying book wholesaler Bertram Group for £29m ($56.9m), in a bid to strengthen its entertainment wholesale business.
Woolworths added that its audio-visual publishing business 2Entertain, a joint venture with the BBC's commercial arm BBC Worldwide, had benefited from DVD sales of natural history series Planet Earth.