The retailer registered a pre-tax profit of£2.4 million for the period, compared with just£300,000 in the same period last year.
Asos chief executive Nick Robertson said: “Particularly pleasing is the increase in profit, which has been delivered as a result of gross margin improvements of 4.7 per cent compared with the same period last year.”
By December 2, Asos had 1.6 million registered users and, according to e-tail traffic monitor Hitwise, Asos.com remains the second most visited online fashion store in the UK, behind Next.
In the six months to September 30, Asos sales rocketed 83 per cent to£31.8 million. Sales for the nine weeks to December 2 shot up 101 per cent.
Asos will deliver a Christmas trading statement at the end of January.