Group sales were up 39 per cent to£18.8 million for the year to March 31.
The company did not trade for five and a half weeks over the Christmas period because its warehouse was damaged in the Buncefield oil depot explosion. Had it not been affected by the disaster, the group estimated sales would have been in the region of£25 million and pre-tax profit approximately£2.2 million.
Over the year, the number of registered users of the web site increased by 60 per cent to 960,000.
The group said its rising profile had enabled it to attract new brands, including Diesel, Firetrap and Replay.
The buying and merchandising team doubled in size during the year, with the number of product lines increasing from 2,000 to 4,000. A new in-house design team will be established over the coming months.
In a statement, the group said the early signs are that 2006/7 would be another strong year, with sales for the 13 weeks to July 2 running 65 per cent ahead of last year.
Chief executive Nick Robertson said: 'The high street is starting to invest in its online offer, so we must ensure we have better capabilities at every level to compete.'
Asos was founded in June 2000 and listed on AIM in October 2001.
Seymour Pierce analyst Richard Ratner said: 'Asos remains one of the most exciting growth stocks in the retail sector, with well above-average profit growth likely at least for the next four to six years.'